Medical observation device and lens barrel of medical observation device

ABSTRACT

To enable a moving object to be movable even when electromotive driving of the moving object is not possible and prevent inconvenience from occurring during medical procedures. A medical observation device includes: an imaging optical system configured to capture an image of a subject; an image sensor configured to photoelectrically convert the image of the subject captured by the imaging optical system; a driving force transmission mechanism configured to have a transmission gear and to transmit a driving force to a moving object; a manual manipulation knob configured to be manipulated to rotate in an axial rotation direction of a fulcrum shaft and to be capable of moving between a first position and a second position in an axial direction of the fulcrum shaft; a switch gear configured to be connected to the manual manipulation knob and to be integrated with the manual manipulation knob and rotate in the axial rotation direction, and to be integrated with the manual manipulation knob and move in the axial direction between a meshing position and a non-meshing position; and a driving motor configured to give a driving force to the moving object. Meshing of the switch gear and the transmission gear is released at the non-meshing position, and the switch gear and the transmission gear mesh with each other at the meshing position.

TECHNICAL FIELD

The present technology relates to the technical field of a medicalobservation device and a lens barrel of the medical observation devicein which a moving object can be moved by both a driving force of adriving motor and manual manipulation.

CITATION LIST Patent Literature

Patent Literature 1: JP 2000-275508A

BACKGROUND ART

There are medical observation devices for observing lesions of patientsin medical procedures and thus achieving efficiency in medicalprocedures, for example, surgical operations, treatments, inspectionscarried out in medical institutes such as hospitals. Such a medicalobservation device is mounted at, for example, a leading end of a robotarm, or the like, and is used to enable a lesion of a patient to beobserved in a desired direction by operating the arm to set a necessaryorientation or angle, and an image or video that it captures isprojected on a display unit such as a monitor or a display.

There are medical observation devices which include driving mechanismsfor moving various moving objects, for example, a zoom lens group, afocus lens group, and the like, and the moving objects like a zoom lensgroup and a focus lens group are moved in a desired direction due todriving forces of driving motors of the driving mechanisms.

However, since the medical observation devices are used in medicalprocedures such as surgical operations, in the unlikely event that amalfunction or failure of the driving mechanisms occurs, big problemscan arise in the medical procedures. Therefore, it is desired to providea configuration in which a moving object can be moved not only throughelectromotive driving of a driving motor but also through manualmanipulation.

As such a configuration in which both electromotive driving and manualmanipulation are possible, for example, there is a configuration inwhich electromotive driving of a zoom lens group based on a drivingforce of a driving motor is performed by manipulating a zoom lever andthe zoom lens group is manually moved by manipulating a zoom ring (forexample, refer to Patent Literature 1).

DISCLOSURE OF INVENTION Technical Problem

However, the medical observation device is used in medical procedures,and thus the medical observation device is often covered and protectedby a transparent sheet called drape during a medical procedure such as asurgical operation.

If a manipulation knob, which is supposed to be manually operated,rotates in an interlinked manner during electromotive driving in thatcase, there is concern of the drape being brought into contact with therotating manipulation knob and thus entwined with the manipulation knob,or damaged.

Therefore, the medical observation device and the lens barrel of themedical observation device of the present technology aim to overcome theabove-described problem by enabling a moving object to be movable evenwhen electromotive driving of the moving object is not possible andpreventing inconvenience from occurring during medical procedures.

Solution to Problem

First, according to the present disclosure, the medical observationdevice includes: an imaging optical system configured to capture animage of a subject; an image sensor configured to photoelectricallyconvert the image of the subject captured by the imaging optical system;a driving force transmission mechanism configured to have a transmissiongear and to transmit a driving force to a moving object; a manualmanipulation knob configured to be manipulated to rotate in an axialrotation direction of a fulcrum shaft and to be capable of movingbetween a first position and a second position in an axial direction ofthe fulcrum shaft; a switch gear configured to be connected to themanual manipulation knob and to be integrated with the manualmanipulation knob and rotate in the axial rotation direction, and to beintegrated with the manual manipulation knob and move in the axialdirection between a meshing position and a non-meshing position; and adriving motor configured to give a driving force to the moving object.Meshing of the switch gear and the transmission gear is released at thenon-meshing position, and the switch gear and the transmission gear meshwith each other at the meshing position.

Accordingly, the switch gear is moved to the non-meshing position whenthe manual manipulation knob is moved to one side and the switch gear ismoved to the meshing position when the manual manipulation knob is movedto the other side.

Second, in the lens barrel, it is desirable that the driving motor beset to be in a non-driving state when the switch gear is moved to themeshing position.

Accordingly, the transmission gear is not rotated due to driving of thedriving motor in the state in which the manual manipulation knob ismanipulated to rotate.

Third, in the lens barrel, it is desirable that: a gear box in which atleast the transmission gear and the switch gear be disposed is provided;and a direction from the first position toward the second position beset to a drawn-out direction of the manual manipulation knob from thegear box.

Accordingly, since the manual manipulation knob is manually manipulatedin the state in which the manual manipulation knob has been drawn outfrom the gear box, the area of a portion of the manual manipulation knobgripped by fingers becomes large.

Fourth, in the lens barrel, it is desirable that: the gear box in whichat least the transmission gear and the switch gear are disposed beprovided; a movement regulation part be provided in the gear box; and aregulated part that is capable of contact with the movement regulationpart when the manual manipulation knob is moved from the first positiontoward the second position be provided in the manual manipulation knob.

Accordingly, movement of the manual manipulation knob with respect tothe gear box is regulated when the regulated part is brought intocontact with the movement regulation part.

Fifth, in the lens barrel, it is desirable that: a gear box in which atleast the transmission gear and the switch gear are disposed and a firstholding engagement part and a second holding engagement part areincluded be provided; a holding member having a position holding part bemounted in the manual manipulation knob; when the manual manipulationknob is moved to the first position, the position holding part beengaged with the first holding engagement part and the switch gear beheld at the non-meshing position; and when the manual manipulation knobis moved to the second position, the position holding part be engagedwith the second holding engagement part and the switch gear be held atthe meshing position.

Accordingly, the gear box has a function of disposing the switch gearand the transmission gear and a function of holding the switch gear atthe meshing position and the non-meshing position.

Sixth, in the lens barrel, it is desirable that: the position holdingpart be capable of elastic deformation; the position holding part slideto the gear box in an elastically deformed state during movement of themanual manipulation knob; and the position holding part be elasticallyrestored and engaged with the first holding engagement part or thesecond holding engagement part.

Accordingly, when the position holding part is engaged with the holdingengagement part, a feeling of a change in an engagement position istransmitted to the hand gripping the manual manipulation knob, causing aso-called click feeling, and an engagement state of the position holdingpart with the holding engagement part is recognized due to the size of aload transmitted during the movement of the manual manipulation knob.

Seventh, in the lens barrel, it is desirable that: the transmission gearbe capable of moving in an axial direction; and a meshing assistingspring configured to urge the transmission gear in a direction to getthe transmission gear close to the switch gear in the axial direction beprovided.

Accordingly, even when the manual manipulation knob is moved and thusthe transmission gear is pressed and moved by the switch gear, themeshing assisting spring causes the transmission gear to move in adirection to get close to the switch gear through rotation manipulationof the manual manipulation knob and both gears mesh with each other.

According to the present technology, the lens barrel of the medicalobservation device includes: an imaging optical system configured tocapture an image of a subject; an image sensor configured tophotoelectrically convert the image of the subject captured by theimaging optical system; a driving force transmission mechanismconfigured to have a transmission gear and to transmit a driving forceto a moving object; a manual manipulation knob configured to bemanipulated to rotate in an axial rotation direction of a fulcrum shaftand to be capable of moving between a first position and a secondposition in an axial direction of the fulcrum shaft; a switch gearconfigured to be connected to the manual manipulation knob, and to beintegrated with the manual manipulation knob and rotate in the axialrotation direction, and to be integrated with the manual manipulationknob and move in the axial direction between a meshing position and anon-meshing position; and a driving motor configured to give a drivingforce to the moving object. Meshing of the switch gear and thetransmission gear is released at the non-meshing position, and theswitch gear and the transmission gear mesh with each other at themeshing position.

Accordingly, the switch gear is moved to the non-meshing position whenthe manual manipulation knob is moved to one side and the switch gear ismoved to the meshing position when the manual manipulation knob is movedto the other side.

Advantageous Effects of Invention

According to the present technology, since the switch gear is moved tothe non-meshing position when the manual manipulation knob is moved toone side and the switch gear is moved to the meshing position when themanual manipulation knob is moved to the other side, a moving object canbe in a movable state even if electromotive driving of the moving objectis not possible, and it is possible to prevent inconvenience fromoccurring during medical procedures.

Note that effects described in the present specification are merelyexamples, and are not limitative, and other effects can be exhibited.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of a medical system including a medicalobservation device, illustrating an embodiment of a medical observationdevice and a lens barrel of the medical observation device of thepresent technology along with FIGS. 2 to 56.

FIG. 2 is a schematic perspective diagram of the medical observationdevice.

FIG. 3 is a perspective diagram of the lens barrel.

FIG. 4 is a perspective diagram of the lens barrel with an omitted partof a front part support housing when viewed in a different directionfrom FIG. 3.

FIG. 5 is a cross-sectional diagram taken along the V-V line of FIG. 3.

FIG. 6 is an enlarged cross-sectional diagram illustrating the innerstructure of a front barrel section.

FIG. 7 is an enlarged perspective diagram illustrating the front endpart of the front barrel section.

FIG. 8 is a vertical cross-sectional diagram of an intermediate barrelsection.

FIG. 9 is a schematic front diagram illustrating a positional relationbetween an iris unit, a second zoom lens holding frame, a driving cam,and the like.

FIG. 10 is an enlarged perspective diagram of the iris unit.

FIG. 11 is an enlarged exploded perspective diagram of the iris unit.

FIG. 12 is an enlarged perspective diagram illustrating the iris unitwhen viewed from the direction opposite to that of FIG. 10.

FIG. 13 is an enlarged perspective diagram illustrating a state in whicha first blade and a second blade are moved to the outermost side.

FIG. 14 is an enlarged perspective diagram illustrating a state in whichthe first blade and the second blade are moved to the innermost side.

FIG. 15 is an enlarged perspective diagram illustrating a state in whicha slide ring and a gear member are assembled with the driving cam.

FIG. 16 is an enlarged exploded perspective diagram illustrating a partof the driving cam, the slide ring, and a stopper screw.

FIG. 17 is an enlarged perspective diagram illustrating a state in whichthe slide ring and the stopper screw are assembled with the driving cam.

FIG. 18 is an enlarged cross-sectional diagram illustrating a state inwhich the slide ring and the stopper screw are assembled with thedriving cam.

FIG. 19 is an enlarged cross-sectional diagram illustrating an operationwhen the driving cam rotates along with FIGS. 20 to 22, and illustratinga state in which the stopper screw is in contact with a regulation pinof a stopper base and the regulation pin regulates rotation of thedriving cam to one side.

FIG. 20 is an enlarged cross-sectional diagram illustrating a state inwhich the driving cam rotates around the slide ring, subsequent to FIG.19.

FIG. 21 is an enlarged cross-sectional diagram illustrating a state inwhich the stopper screw is pressed by a regulation edge and the slidering and the stopper screw rotate integrally with the driving cam,subsequent to FIG. 20.

FIG. 22 is an enlarged cross-sectional diagram illustrating a state inwhich the stopper screw pressed by the regulation edge is in contactwith the regulation pin to regulate rotation of the driving cam 60, andthus the driving cam reaches a rotation end on the other side,subsequent to FIG. 21.

FIG. 23 is an enlarged perspective diagram illustrating a gear box andrespective parts disposed in the gear box.

FIG. 24 is an enlarged side diagram illustrating the gear box andrespective parts disposed in the gear box.

FIG. 25 is an enlarged bottom diagram illustrating an operating body, adetection switch, and the like.

FIG. 26 is an enlarged cross-sectional diagram illustrating the gear boxand the respective parts disposed in the gear box, and a state in whicha manual manipulation knob is at a first position and a switch gear isat a non-meshing position.

FIG. 27 is an enlarged cross-sectional diagram illustrating the gear boxand the respective parts disposed in the gear box, and a state in whichthe manual manipulation knob is at a second position and the switch gearis at a meshing position.

FIG. 28 is an enlarged cross-sectional diagram illustrating the gear boxand the respective parts disposed in the gear box, and a state in whichthe manual manipulation knob is moved to the second position and theswitch gear does not mesh with a transmission gear.

FIG. 29 is an enlarged perspective diagram of a rear barrel section.

FIG. 30 is an enlarged perspective diagram of the rear barrel sectionviewed in a different direction from FIG. 29.

FIG. 31 is an enlarged cross-sectional diagram of the rear barrelsection.

FIG. 32 is an enlarged perspective diagram illustrating the case body ofa rear support housing.

FIG. 33 is an enlarged perspective diagram illustrating the case body ofthe rear support housing viewed in a different direction from FIG. 32.

FIG. 34 is an enlarged perspective diagram illustrating the case body ofthe rear support housing viewed in a different direction from FIGS. 32and 33.

FIG. 35 is an enlarged perspective diagram illustrating the rear barrelsection from which a seal member and an element unit are removed.

FIG. 36 is an enlarged perspective diagram of an operating lever.

FIG. 37 is an enlarged exploded perspective diagram illustrating a clicklever and a urging spring.

FIG. 38 is an enlarged perspective diagram of a cylindrical cap.

FIG. 39 is an enlarged perspective diagram of an element holding frame.

FIG. 40 is an enlarged perspective diagram illustrating the elementholding frame viewed in a different direction from FIG. 39.

FIG. 41 is an enlarged perspective diagram illustrating the elementholding frame viewed from a different direction from FIGS. 39 and 40.

FIG. 42 is an enlarged cross-sectional diagram illustrating the elementholding frame and an optical element mounted in the element holdingframe.

FIG. 43 is an enlarged perspective diagram illustrating a rotationoperation of the element holding frame along with FIGS. 44 to 51,illustrating a state in which the element holding frame is held at anintermediate position.

FIG. 44 is an enlarged cross-sectional diagram illustrating the elementholding frame held at the intermediate position.

FIG. 45 is an enlarged perspective diagram illustrating a state in whichthe element holding frame is held at the intermediate position and adetection piece of the element holding frame is positioned between twoposition detection sensors.

FIG. 46 is an enlarged perspective diagram illustrating a state in whichthe element holding frame is held at a first turn position.

FIG. 47 is an enlarged cross-sectional diagram illustrating a state inwhich the element holding frame is held at the first turn position.

FIG. 48 is an enlarged perspective diagram illustrating a state in whichthe element holding frame is held at the first turn position and thedetection piece of the element holding frame is positioned betweendetectors of one position detection sensor.

FIG. 49 is an enlarged perspective diagram illustrating a state in whichthe element holding frame is held at a second turn position.

FIG. 50 is an enlarged cross-sectional diagram illustrating a state inwhich the element holding frame is held at the second turn position.

FIG. 51 is an enlarged perspective diagram illustrating a state in whichthe element holding frame held at a third turn position and thedetection piece of the element holding frame positioned betweendetectors of one position detection sensor.

FIG. 52 is a schematic enlarged cross-sectional diagram illustrating anexample in which a rotation position of the element holding frame ismagnetically detected, along with FIGS. 53 and 54, and a state in whichthe intermediate position has been detected.

FIG. 53 is a schematic enlarged cross-sectional diagram illustrating astate in which a first turn position has been detected.

FIG. 54 is a schematic enlarged cross-sectional diagram illustrating astate in which a second turn position has been detected.

FIG. 55 is a schematic cross-sectional diagram illustrating an examplein which five optical elements are held in the element holding frame.

FIG. 56 is a schematic cross-sectional diagram illustrating, in theexample in which the five optical elements are held in the elementholding frame, a state in which an optical element held at one end ofthe element holding frame is positioned at an optical axis.

MODE(S) FOR CARRYING OUT THE INVENTION

An embodiment for implementing the present technology will be describedbelow with reference to the accompanying drawings.

A medical observation device according to the embodiment to be describedbelow is an imaging device that can photograph dynamic images and stillimages, and is formed in a shape stretching in one direction, having anoptical axis direction in the longitudinal direction.

Description will be provided below on the premise that the optical axisdirection is the front-rear direction and predetermined respectivedirections orthogonal to the optical axis are the up-down direction andthe left-right direction. In addition, description will be provided bysetting a subject side as front and a direction in which an image of asubject is taken as rear.

Note that the front, rear, up, down, left, and right directions to bedescribed below are for the sake of convenience in description, and anembodiment of the present technology is not limited to these directions.

Furthermore, a lens group to be described below is constituted of asingle lens or a plurality of lenses, and may include the single lens orplurality of lenses and other optical elements such as a diaphragm or aniris.

[Schematic Configuration of Medical System]

First, a schematic configuration of a medical system in which themedical observation device is used will be described (with reference toFIG. 1).

The medical system 1000 is a system installed in an indoor area 900, forexample, an operation room or an examination room of a hospital, andincludes a robot arm device 180 and a display device 190.

The robot arm device 180 has a base 181 installed on a floor 200, etc.,and an arm 182 connected to the base 181.

The base 181 may be installed in a fixed state, and movable on the floor200, or the like. The arm 182 has a plurality of links 182 a, 182 a, . .. , and joints 182 b, 182 b, . . . which connect the links 182 a, 182 a,. . . to be turnable. The link 182 a connected to the base 181 can beturned with respect to the base 181 due to the joint 182 b.

A medical observation device 1 is mounted in the link 182 a on the mostleading end side. Since the links 182 a, 182 a, . . . of the arm 182 areturnable with respect to other the links 182 a, 182 a, . . . or the base181 due to the joints 182 b, 182 b, the links 182 a, 182 a, . . . arerotated in a desired direction and by a desired angle, and thus themedical observation device 1 can be disposed at a desired positionhaving a desired orientation.

When a medical procedure such as a surgical operation or an examinationis performed in the indoor area 900, the robot arm device 180 andmedical observation device 1 are covered by a sterilization-processedtransparent protection sheet 300, which is called a drape. Thus, manualmanipulation with respect to a manipulation unit of the medicalobservation device 1 by an operator 700, such as a doctor, is performedfrom the outside of the protection sheet 300 in a state in which theprotection sheet 300 overlaps the manipulation unit and thus theoperator grips them together.

The display device 190 is mounted in a wall 400, or the like, and has adisplay unit 191 such as a display on which images or videos captured bythe medical observation device 1 are projected. Note that the displaydevice 190 may be a monitor device disposed on a table in a fixed stateor a movable state, or a monitor device installed to be fixed to ormovable on the floor 200, or the like.

A procedure table 500, for example, an operating table, an examinationbed, or the like is disposed in the indoor area 900, and a proceduresubject 600 such as a patient or an examinee lies on the procedure table500. The operator 700 such as a doctor performs, for example, a medicalprocedure on a lesion of the procedure subject 600 using a medicalinstrument 800 such as a scalpel or a forceps.

When the operator 700 performs the medical procedure for the proceduresubject 600, an image or video of the lesion of the procedure subject600 is captured by the medical observation device 1, and the capturedimage or video is projected on the display unit 191 of the displaydevice 190. The operator 700 performs the medical procedure whileviewing the image or video projected on the display unit 191 and thelesion.

Note that, during the medical procedure, or the like, the robot armdevice 180 may be operated and the links 182 a, 182 a, . . . turnedelectrically, or the operator 700, or the like may grip the medicalobservation device 1 or the links 182 a, 182 a, . . . to manually turnthe links 182 a, 182 a, . . . in a desired direction at a desired angle.

Thus, when the operator 700 or the like grips the medical observationdevice 1, in particular, it is desirable for the medical observationdevice 1 to be miniaturized in its radial direction in order to achieveenhancement in a grip property of the medical observation device 1.

In addition, the operator 700 often performs medical procedures whileviewing lesions. Thus, miniaturizing the medical observation device 1 inits radial direction is particularly important to prevent the medicalobservation device 1 from obstructing visual recognition when a lesionis visually recognized.

Note that the medical observation device 1 may be configured to berotatable with respect to the link 182 a at the most leading end side inan arbitrary direction, and in this case, an orientation of the medicalobservation device 1 can be easily and smoothly set.

[Schematic Configuration of Medical Observation Device]

Next, a schematic configuration of the medical observation device 1 willbe described (with reference to FIG. 2).

The medical observation device 1 has a portion excluding a part of alens barrel to be described below disposed inside an outer housing 2.

The outer housing 2 has a main body 3 formed in a shape stretching inthe front-rear direction and a mounted section 4 that protrudes from arear end of the main body 3.

The main body 3 is formed such that a front section 5 that issubstantially a front half portion of the main body is smaller than arear section 6 that is substantially a rear half portion thereof.

The front section 5 is formed in a cylindrical shape, and a cover 7 atleast a part of which is transparent is mounted in the front end part ofthe front section 5.

The rear section 6 has an outer circumference part 8 formed in asubstantially cylindrical shape and a circular rear face part 9 that isconnected to the rear end of the outer circumference part 8. The outercircumference part 8 has insertion holes formed in the circumferentialdirection at the positions that are opposed to each other by about 180°.

The mounted section 4 protrudes to a side from a rear end part of therear section 6. The mounted section 4 is mounted in the link 182 a onthe most leading end side of the robot arm device 180.

[Schematic Configuration of Lens Barrel]

Next, a schematic configuration of the lens barrel will be described(with reference to FIGS. 3 and 4).

The lens barrel 10 is formed combining the front barrel section 11, theintermediate barrel section 12, and the rear barrel section 13 in thatorder from the front side in a shape stretching in the front-reardirection as a whole. The lens barrel 10 has an imaging optical systemhaving various lenses and the like to image a subject and an imagesensor that photoelectrically converts an image of the subject capturedby the imaging optical system, and the direction in which the imagingoptical system and the image sensor are connected (the front-reardirection) is set to be the optical axis direction.

The lens barrel 10 has the imaging optical system provided as abinocular optical system, respective elements of the imaging opticalsystem such as lenses are disposed on the left and right in theintermediate barrel section 12 and the rear barrel section 13, and thuslight coming during imaging is incident on the respective left opticalsystem and right optical system, thereby forming two light paths. Inthis manner, the lens barrel 10 receives light incident on the tworespective optical systems, and thus can acquire a stereoscopic imageusing parallax of the incident light.

Excluding a lens group disposed on the rear end side, elements of theimaging optical system of the front barrel section 11 such as lenses arenot disposed from left to right, and light that is taken in has onepath. The front barrel section 11 is designed to be an objective systemand mainly has a function of taking in light and a focusing function ofputting focus on the light that is taken in. Thus, a focusing mechanismis disposed on the front barrel section 11.

The intermediate barrel section 12 is an image-forming system, andmainly has a zooming function of changing magnification by changing thediameter of light that is taken in. Thus, a zooming mechanism isdisposed in the intermediate barrel section 12.

The rear barrel section 13 is an image-forming system, and mainly has afunction of acquiring images of light that is taken in with differentspectral characteristics. Specifically, a switching mechanism which canswitch a plurality of optical elements of different kinds, for example,optical filters, is disposed in the rear barrel section 13, and thusimages with different spectral characteristics can be acquired as theswitching mechanism switches the optical filters. In addition, two imagesensors which photoelectrically convert subject images captured by theimaging optical system are disposed on the left and right in a rear endpart of the rear barrel section 13.

[Specific Configuration of Lens Barrel]

Next, a specific configuration of the lens barrel 10 will be described.

The lens barrel 10 is configured by combining the front barrel section11, the intermediate barrel section 12, and the rear barrel section 13in order from the front side as described above, and thus descriptionwill be provided below in order of the front barrel section 11, theintermediate barrel section 12, and the rear barrel section 13.

<Configuration of Front Barrel Section>

First, a configuration of the front barrel section 11 will be described(refer to FIGS. 3 to 7).

The front barrel section 11 has respective necessary parts disposedinside and outside a front part support housing 14 (refer to FIG. 3 toFIG. 5). The front barrel section 11 is disposed inside the main body 3of the outer housing 2.

The front part support housing 14 has outer circumferential members 15and 15 that stretch forward and backward, a first coupling member 16that is mounted on the outer circumferential members 15 and 15, and aframe-shaped second coupling member 17 that is mounted on the outercircumferential members 15 and 15.

The outer circumferential members 15 and 15 are positioned separatelyfrom each other on the left and right, and are formed in a substantiallycircular arc shape projecting outward (to the sides).

The first coupling member 16 has a frame shape part 16 a having a holepenetrating it forward and backward, a protrusion part 16 b thatprotrudes rearward from an upper end part of the frame shape part 16 a,and a connection protrusion part 16 c that protrudes rearward from alower end part of the frame shape part 16 a. The frame shape part 16 ais mounted in the front end part of the outer circumferential members 15and 15. The protrusion part 16 b is positioned between the upper endparts of the outer circumferential members 15 and 15. The connectionprotrusion part 16 c is positioned between the lower end parts of theouter circumferential members 15 and 15.

The second coupling member 17 is mounted on the rear end parts of theouter circumferential members 15 and 15.

The frame shape part 16 a of the first coupling member 16 and the secondcoupling member 17 are formed in an oval shape that extendssubstantially horizontally, their upper and lower parts are formed tostretch to the left and right substantially linearly, and their left andright side parts are formed in a substantially circular arc shapeprojecting outward (to the sides). Thus, with the lens barrel 10disposed inside the main body 3 of the outer housing 2, respectivespaces are formed between the upper end parts and the lower end parts ofthe outer circumferential members 15 and 15, and thus the spaces are afirst disposition space 11 a and a second disposition space 11 b (referto FIG. 6).

Guiding shafts 18 and 18 that stretch forward and backward are disposedseparately from each other on the upper and lower sides between theframe shape part 16 a of the first coupling member 16 and the secondcoupling member 17 (refer to FIG. 4 to FIG. 6). The front end parts ofthe guiding shafts 18 and 18 are mounted on the upper end part and thelower end part of the frame shape part 16 a, and the rear end partsthereof are mounted on the upper end part and the lower end part of thesecond coupling member 17.

A front-end-side lens group 19 is held in the frame shape part 16 a ofthe first coupling member 16 (refer to FIGS. 3 to 6). The front-end-sidelens group 19 is disposed in a fixed state and formed in an oval shapethat extends substantially horizontally.

First lens groups 20 and 20 are held on the left and right sides in thesecond coupling member 17 (refer to FIG. 5). The first lens groups 20and 20 are disposed in a fixed state.

A support plate 21 is mounted on an upper end part of the front partsupport housing 14, and thus the support plate 21 is positioned in thefirst disposition space 11 a (refer to FIGS. 3, 4 and 6). The supportplate 21 has an extending face part 21 a that stretches forward andrearward, a support face part 21 b that protrudes downward from thefront end part of the extending face part 21 a, and a motor-mounted facepart 21 c that protrudes downward from the rear end part of theextending face part 21 a.

A lead screw 22 that stretches forward and rearward supports the supportplate 21. Both the front and rear ends of the lead screw 22 aresupported to be freely rotated with respect to respective parts of thesupport plate 21, and positioned in the first disposition space 11 a.

The focus motor 23 is mounted on the motor-mounted face part 21 c of thesupport plate 21 (refer to FIGS. 4 and 6). A portion of the focus motor23 excluding its motor shaft is mounted on the rear face side of themotor-mounted face part 21 c, and the motor shaft penetrates themotor-mounted face part 21 c from the rear side. The focus motor 23 ispositioned on the outer face side of the front part support housing 14.

When the motor shaft rotates in the focus motor 23, a driving force ofthe focus motor 23 is transmitted to the lead screw 22 through the motorshaft, and thus the lead screw 22 rotates in the direction according tothe rotation direction of the motor shaft.

A focus frame 24 is supported by the guiding shafts 18 and 18 to befreely slidable (refer to FIGS. 4 to 6). The focus frame 24 has a lensholding part 24 a formed in an oval shape that extends substantiallyhorizontally, and supported protrusion parts 24 b and 24 b that protrudeupward and downward from the lens holding part 24 a. The focus frame 24is supported such that the supported protrusion parts 24 b and 24 b arefreely slidable with respect to the guiding shafts 18 and 18.

A focus lens 25 is held by the lens holding part 24 a of the focus frame24. The focus lens 25 is formed in an oval shape that extendssubstantially horizontally.

A nut member 26 is supported by the supported protrusion parts 24 b onthe upper side of the focus frame 24. A part of the nut member 26 isprovided as a screw part 26 a, and thus the screw part 26 a is screwedonto the lead screw 22. When a driving force of the focus motor 23causes the lead screw 22 to rotate, the nut member 26 is sent in thedirection according to the rotation direction of the lead screw 22, andthe focus frame 24 holding the focus lens 25 is guided by the guidingshafts 18 and 18 and moved in the front-rear direction (the optical axisdirection), and thereby focusing is performed.

Mounting plates 27 and 27 are mounted on upper and lower end parts ofthe front part support housing 14 (refer to FIG. 7). Each mounting plate27 has a mounted plate part 27 a that stretches forward and rearward,and a mounting part 27 b that protrudes upward and downward from thefront end part of the mounted plate part 27 a. The mounting parts 27 band 27 b of the mounting plates 27 and 27 have light sources 28 and 28such as light emitting diodes installed therein, and the light sources28 and 28 are respectively immediately above and below thefront-end-side lens group 19.

The light sources 28 and 28 have a function of improving visibility of alesion of the procedure subject 600 by irradiating the lesion during amedical procedure and helping acquire bright and vivid images andvideos.

The upper-side mounting plate 27 and the upper-side light source 28 arepositioned in the first disposition space 11 a, and the lower-sidemounting plate 27 and the lower-side light source 28 are positioned inthe second disposition space 11 b.

In the medical observation device 1, the front-end-side lens group 19and the focus lens 25 are formed in the oval shape that extendssubstantially horizontally as described above, thereby being formed in aso-called D-cut shape obtained by cutting upper and lower end parts of acircular shape out, the first disposition space 11 a is formed on theupper side of the front part support housing 14, and the seconddisposition space 11 b is formed on the lower side of the front partsupport housing 14.

Since the first disposition space 11 a is formed on the upper side ofthe front part support housing 14 as described above, a focus drivingmechanism having the support plate 21, the lead screw 22, and the likecan be disposed in the first disposition space 11 a, and thus it isunnecessary to increase the size of the front barrel section 11 tosecure a disposition space of the focus driving mechanism, and themedical observation device 1 can be minimized with a sufficientdisposition space of the focus driving mechanism secured.

In addition, the first disposition space 11 a and the second dispositionspace 11 b are formed on the upper and lower sides of the front partsupport housing 14 in the medical observation device 1.

Thus, the mounting plates 27 and 27 and the light sources 28 and 28 canbe disposed in the first disposition space 11 a and the seconddisposition space 11 b, and it is accordingly unnecessary to increasethe size of the front barrel section 11 to secure disposition spaces ofthe mounting plates 27 and 27 and the light sources 28 and 28, and thusthe medical observation device 1 can be minimized with a sufficientdisposition space of the mounting plates 27 and 27 and the light sources28 and 28.

Furthermore, by disposing the support plate 21, the lead screw 22, themounting plates 27 and 27, and the light sources 28 and 28 in the firstdisposition space 11 a or the second disposition space 11 b, the medicalobservation device 1 can be minimized, and thus can be easily grippedwhen the operator 700 or the like grips the medical observation device1, and thereby a gripping property can be improved.

Moreover, the light sources 28 and 28 are positioned at the front endpart of the medical observation device 1, and thus shadows are rarelygenerated on a lesion of the procedure subject 600 when the lightsources 28 and 28 illuminate the lesion, and therefore visibility of thelesion can be improved and clear and vivid images and videos can beacquired.

<Configuration of Intermediate Barrel Section>

Next, a configuration of the intermediate barrel section 12 will bedescribed (with reference to FIGS. 3, 4, and 5, and FIGS. 8 to 28).

The intermediate barrel section 12 has an intermediate support housing29 and respective necessary parts mounted or supported inside andoutside of the intermediate support housing 29 (refer to FIGS. 3 to 5).The intermediate barrel section 12 is disposed inside the main body 3 ofthe outer housing 2, excluding a part of the manual manipulation knob tobe described below.

The intermediate support housing 29 has a circumferential face part 29 athat is formed in a substantially cylindrical shape stretching forwardand rearward, and a rear face part 29 b provided to block the opening onthe rear side of the circumferential face part 29 a as illustrated inFIGS. 5 and 8, and the rear face part 29 b has two transmissive holes,which are not illustrated, formed on the left and right sides.

The rear face of a connection member 30 that blocks an opening on thefront side of the circumferential face part 29 a is mounted on the frontend part of the intermediate support housing 29. The connection member30 has two light-transmissive holes, which are not illustrated, formedon the left and right sides. The connection member 30 is mounted on thesecond coupling member 17 of the front part support housing 14 at itsrear side.

Guiding shafts 31 and 31 that stretch forward and rearward are disposedin the intermediate support housing 29, separately from each other onthe upper and lower sides in a fixed state. The front end part and therear end part of the guiding shafts 31 and 31 are respectively mountedin the connection member 30 and the rear face part 29 b of theintermediate support housing 29.

A first zoom lens holding frame 32 is supported by the guiding shafts 31and 31 to be freely slidable. A cam pin 32 a that protrudes upward isprovided in the first zoom lens holding frame 32 (refer to FIG. 8).Second lens groups 33 and 33 are arranged on the left and right sidesand held by the first zoom lens holding frame 32 (refer to FIGS. 5 and9).

A second zoom lens holding frame 34 is supported by the guiding shafts31 and 31 to be freely slidable (refer to FIGS. 5, 8 and 9). The secondzoom lens holding frame 34 has a lens holding part 35 formed in a shapethat extends horizontally, shaft-supported parts 36 and 36 that protrudefrom the lens holding part 35, mounting protrusion parts 37 and 37 thatprotrude from the left and right of the lens holding part 35, and a campin 38 that protrudes upward from the center of the lens holding part 35in the left-right direction. A disposition notch 35 a that opensdownward is formed at the center of the lens holding part 35 in theleft-right direction (refer to FIG. 9).

Third lens groups 39 and 39 are held by the lens holding part 35 on theleft and right sides.

An iris unit 40 is mounted in the second zoom lens holding frame 34(refer to FIGS. 5 and 9). The iris unit 40 has a base plate 41 formed ina shape that extends horizontally, a first blade 42 supported to befreely slidable with respect to the base plate 41, a second blade 43supported to be freely slidable with respect to the base plate 41, apressing plate 44 mounted on the base plate 41, and an iris motor 45mounted on the base plate 41, as illustrated in FIG. 10 and FIG. 11.

The base plate 41 has a plate-shaped base part 46 that faces thefront-rear direction, mounted protrusion parts 47 and 47 that eachprotrude rearward from the left and right end parts of the base part 46,and a motor attachment part 48 that protrudes rearward from the lowerend part of the center of the base part 46 in the left-right direction.

Circular through holes 46 a and 46 a are formed separately from eachother on the left and right sides of the base part 46. Four guidingshafts 46 b, 46 b, . . . that protrude rearward are provided on thefront face of the base part 46 separately from each other on the upper,lower, left, and right sides (refer to FIGS. 11, 13 and 14). Shaftinsertion holes 46 c and 46 c that are penetrated forward and rearwardare formed at lower end positions of the base part 46, separately fromeach other on the upper and lower sides, the upper shaft insertion hole46 c is formed in a circular arc shape projecting upward, and the lowershaft insertion hole 46 c is formed in a circular arc shape projectingdownward. Slide protrusion threads 46 d, 46 d, . . . stretching to theleft and right and projecting upward are provided on the front face ofthe base part 46, separately from each other on the upper, lower, leftand right sides.

The first blade 42 is formed in a sheet shape of which the thicknessdirection is the front-rear direction, and thereby is formed in a shapethat extends horizontally. A light amount control notch 49 is formed atthe left end part of the first blade 42. The portion of the light amountcontrol notch 49 excluding its right end part is formed as asemi-circular part 49 a formed in a substantially semi-circular shape,and the right end part is formed as a pointy part 49 b formed insubstantially an isosceles triangle shape projecting rightward. A lightamount control hole 50 is formed in the right half part of the firstblade 42. The part of the light amount control hole 50 excluding theright end part is formed as a circular part 50 a formed in asubstantially circular shape, and the right end part is formed as apointy part 50 b formed in substantially an isosceles triangle shapeprojecting rightward.

Four guided holes 42 a, 42 a, . . . that stretch to the left and rightare formed in the first blade 42, separately from each other on theupper, lower, left, and right sides. A work hole 42 b is formed at alower end part of the center of the first blade 42 in the left-rightdirection, and the work hole 42 b is formed in a linear shape stretchingup and down. A shaft movement hole 42 c is formed at a position near thelower end of the center of the first blade 42 in the left-rightdirection, and the shaft movement hole 42 c is formed in a circular arcshape projecting upward.

The guide shafts 46 b, 46 b, . . . are inserted into the guided holes 42a, 42 a, . . . , and thus the first blade 42 is supported by the basepart 46 of the base plate 41 to be freely slidable in the left-rightdirection.

The second blade 43 is formed in a sheet shape of which the thicknessdirection is the front-rear direction, thereby being formed in a shapethat extends horizontally. A light amount control hole 51 is formed inthe left half part of the second blade 43. The part of the light amountcontrol hole 51 excluding the left end part is formed as a circular part51 a formed in a substantially circular shape, and the left end part isformed as a pointy part 51 b formed in substantially an isoscelestriangle shape projecting leftward. A light amount control notch 52 isformed at the right end part of the second blade 43. The part of thelight amount control notch 52 excluding the left end part is formed as asemi-circular part 52 a formed in a substantially semi-circular shape,and the left end part is formed as a pointy part 52 b formed insubstantially an isosceles triangle shape projecting leftward.

Four guided holes 43 a, 43 a, . . . that stretch to the left and rightare formed in the second blade 43, separately from each other on theupper, lower, left, and right sides. A work hole 43 b is formed at alower end part of the center of the second blade 43 in the left-rightdirection, and the work hole 43 b is formed in a linear shape stretchingup and down.

The second blade 43 overlaps the first blade 42 supported by the basepart 46 from its front side, the respective guide shafts 46 b, 46 b, . .. are inserted into the guided holes 43 a, 43 a, . . . , and thus thesecond blade is supported by the base part 46 of the base plate 41 to befreely slidable in the left-right direction.

In the state in which the first blade 42 and the second blade 43 aresupported by the base part 46, at least a part of the light amountcontrol notch 49 and at least a part of the light amount control hole 51are positioned on the front side of one through hole 46 a of the basepart 46, and at least a part of the light amount control hole 50 and atleast a part of the light amount control notch 52 are positioned on thefront side of the other through hole 46 a of the base part 46.

The pressing plate 44 is formed in a sheet shape of which the thicknessdirection is the front-rear direction, thereby being formed in a shapethat extends horizontally. Circular holes 44 a and 44 a are formed inthe pressing plate 44, separately from each other on the left and rightsides. Shaft holes 44 b and 44 b are formed at lower end positions ofthe center of the pressing plate 44 in the left-right direction,separately from each other on the upper and lower sides. The upper shafthole 44 b is formed in a circular arc shape projecting upward, and thelower shaft hole 44 b is formed in a circular arc shape projectingdownward.

Slide protrusion threads 44 c, 44 c, . . . stretching to the left andright with a rearward convex extrusion shape are provided in thepressing plate 44, separately from each other on the upper, lower, left,and right sides. The slide protrusion threads 44 c, 44 c, . . . increasestrength of the pressing plate 44.

The pressing plate 44 overlaps the second blade 43 from its front sidethat overlaps the first blade 42 from its front side, and then ismounted on the base part 46 of the base plate 41. Thus, the pressingplate 44 presses the first blade 42 and the second blade 43 from theirfront sides, and exfoliation of the first blade 42 and the second blade43 from the base part 46 is prevented.

In addition, in the state in which the pressing plate 44 is mounted onthe base part 46, the slide protrusion threads 46 d, 46 d, . . . of thebase part 46 come in contact with the rear surface of the first blade42, and the slide protrusion threads 44 c, 44 c, . . . of the pressingplate 44 come in contact with the second blade 43.

In the state in which the pressing plate 44 is mounted on the base part46, at least a part of the light amount control notch 49 and at least apart of the light amount control hole 51 are positioned on the rear sideof one circular hole 44 a, and at least a part of the light amountcontrol hole 50 and at least a part of the light amount control notch 52are positioned on the rear side of the other circular hole 44 a (referto FIG. 12).

The iris motor 45 is mounted on the motor mounting part 48 of the baseplate 41 on its rear side (refer to FIGS. 10 and 11). A driving memberis connected to the motor shaft of the iris motor 45, which is notillustrated, and work shafts 53 and 53 that protrude forward areprovided in the driving member. The work shafts 53 and 53 are positionedthe same distance from the motor shaft in the radial direction havingthe motor shaft as its center. Thus, when the driving member is rotateddue to a driving force of the iris motor 45, the work shafts 53 and 53move around the motor shaft of the iris motor 45 in the circumferentialdirection.

The one work shaft 53 is inserted into the shaft insertion hole 46 c ofthe base part 46, the shaft movement hole 42 c of the first blade 42,the work hole 43 b of the second blade 43, and the upper shaft hole 44 bof the pressing plate 44 in order as illustrated in FIG. 13, and engagedwith the work hole 43 b to be freely slidable. The other work shaft 53is inserted into the lower shaft insertion hole 46 c of the base part46, the work hole 42 b of the first blade 42, and the lower shaft hole44 b of the pressing plate 44 in order, and engaged with the work hole42 b to be freely slidable.

In the iris unit 40 configured as described above, when the work shafts53 and 53 are turned due to driving of the iris motor 45, the workshafts 53 and 53 respectively slide along the opening edge of the workhole 42 b of the first blade 42 and the opening edge of the work hole 43b of the second blade 43, and thus the first blade 42 and the secondblade 43 are guided by the guide shafts 46 b, 46 b, . . . of the baseplate 41 and slide with respect to the base part 46 in the left-rightdirection (refer to FIGS. 13 and 14).

At this time, the first blade 42 slides along the slide protrusionthreads 46 d, 46 d, . . . provided in the base part 46 of the base plate41, and thus a contact area of the first blade 42 with the base part 46is small, a load of the sliding operation of the first blade 42 isreduced, and therefore a smooth sliding operation of the first blade 42can be achieved.

In addition, the second blade 43 slides along the slide protrusionthreads 44 c, 44 c, . . . provided in the pressing plate 44, and thus acontact area of the second blade 43 with the pressing plate 44 is small,a load of the sliding operation of the second blade 43 is reduced, andtherefore a smooth sliding operation of the second blade 43 can beachieved.

When the first blade 42 and the second blade 43 respectively slideoutward due to turning of the work shafts 53 and 53 to one side, sizesof an opening 54 formed by the light amount control notch 49 and thelight amount control hole 51 and an opening 55 formed by the lightamount control hole 50 and the light amount control notch 52 becomegreater together as illustrated in FIG. 13, and thus an amount of lightpenetrating the openings 54 and 55 increases.

On the other hand, when the first blade 42 and the second blade 43 slideinward due to turning of the work shafts 53 and 53 to the other side,the sizes of the opening 54 formed by the light amount control notch 49and the light amount control hole 51 and the opening 55 formed by thelight amount control hole 50 and the light amount control notch 52become smaller together as illustrated in FIG. 14, and thus an amount oflight penetrating the openings 54 and 55 decreases.

At this time, in a state in which the first blade 42 and the secondblade 43 slide to the innermost side, the opening 54 is formed by apointy part 49 b of the light amount control notch 49 and the pointypart 51 b of the light amount control hole 51, and the opening 55 isformed by the pointy part 50 b of the light amount control hole 50 andthe pointy part 52 b of the light amount control notch 52 as illustratedin FIG. 14. Thus, there are no cases in which the openings 54 and 55 arenot formed in the iris unit 40 even in the state in which the firstblade 42 and the second blade 43 slide to the innermost side, andtherefore there is an amount of light penetrating the openings 54 and55.

Note that, when the first blade 42 and the second blade 43 slide to theinner side, at least one guide shaft 46 b of the base plate 41 comes incontact with the end edge of the guided hole 42 a of the first blade 42or the end edge of the guided hole 43 a of the second blade 43, and thusfurther sliding of the first blade 42 or the second blade 43 to theinner side is regulated. Therefore, at least one guide shaft 46 b of thebase plate 41 functions as a stopper shaft which regulates sliding ofthe first blade 42 or the second blade 43 to the inner side.

Since the through holes 46 a and 46 a are not completely blocked andthere is an amount of light penetrating the openings 54 and 55 in theiris unit 40 even in the state in which the first blade 42 and thesecond blade 43 slide to the innermost side as described above, thereare no cases in which images or videos are not projected during medicalprocedures, and thus the medical procedures can be sped up andimprovement in safety of the medical procedures can be achieved.

Furthermore, the driving member having the two work shafts 53 and 53 isconnected to the motor shaft of the iris motor 45 in the iris unit 40,and both the first blade 42 and the second blade 43 slide in theleft-right direction due to driving of the iris motor 45.

Thus, since the first blade 42 and the second blade 43 operate due tothe driving of the one iris motor 45, it is not necessary to providedifferent motors for respective driving of the first blade 42 and thesecond blade 43, and accordingly a reduction in manufacturing costs,miniaturization, and reliability in operations of the medicalobservation device 1 can be achieved.

Moreover, in the iris unit 40, the light amount control notch 49 and thelight amount control hole 50 are formed to form the left and rightopenings 54 and 55 in the first blade 42, and the light amount controlhole 51 and the light amount control notch 52 are formed to form theleft and right openings 54 and 55 in the second blade 43.

Therefore, since a total of four blades, among which two blades form theopenings 54 and 55, are not necessary for a binocular optical system,further reduction in manufacturing costs, miniaturization, andreliability in operations of the medical observation device 1 can beachieved.

The iris unit 40 is mounted in the second zoom lens holding frame 34(refer to FIGS. 5 and 9). As the mounted protrusion parts 47 and 47 ofthe base plate 41 are engaged with the mounting protrusion parts 37 and37 and a predetermined part is screwed, the iris unit 40 is mounted inthe second zoom lens holding frame 34 from its front side.

In the state in which the iris unit 40 is mounted in the second zoomlens holding frame 34, the iris motor 45 positioned to protrude rearwardfrom the base plate 41 and the driving member mounted on the iris motor45 are positioned in the disposition notch 35 a formed in the secondzoom lens holding frame 34 (refer to FIG. 9). Thus, the iris motor 45and the driving member are positioned on the lower side near the secondzoom lens holding frame 34.

Since the disposition notch 35 a is formed in the second zoom lensholding frame 34 and the iris motor 45 and the driving member arepositioned in the disposition notch 35 a in the state in which the irisunit 40 is mounted in the second zoom lens holding frame 34 as describedabove, the disposition space of the iris motor 45 and the driving membercan attain efficiency, and miniaturization of the medical observationdevice 1 can be achieved accordingly. Particularly, miniaturization ofthe medical observation device 1 in the diameter direction can beachieved, and thus the medical observation device 1 can be easilygripped when gripped by the operator 700 or the like, and thereby agripping property can be improved.

A driving motor 56, an encoder 57, and a gear head 58 are disposed atthe front and back on the left end side of the upper end part of theintermediate support housing 29 (refer to FIG. 3).

The driving motor 56 is positioned between the encoder 57 and the gearhead 58, the encoder 57 is positioned in front of the driving motor 56,and the gear head 58 is positioned behind the driving motor 56.

The encoder 57 has a function of detecting an amount of rotation of thedriving motor 56.

The gear head 58 has a gear group disposed inside that is notillustrated and a feeding gear 58 a disposed in its rear end part (referto FIGS. 3 and 9), and is rotated by a driving force of the drivingmotor 56.

A gear body 59 is disposed near the gear head 58 in the intermediatesupport housing 29, and the gear body 59 has an intermediate gear 59 a.The intermediate gear 59 a meshes with the feeding gear 58 a of the gearhead 58.

A shaft-shaped driving cam 60 that stretches forward and rearward issupported in the upper end part inside the intermediate support housing29 to be freely rotatable (refer to FIG. 8). The driving cam 60 isconstituted by a cam forming part 61 of which the diameter is largest, awork part 62 that protrudes forward from the cam forming part 61, afront supported shaft part 63 that protrudes forward from the work part62, a gear mounting part 64 that protrudes rearward from the cam formingpart 61, and a rear supported shaft part 65 that protrudes rearward fromthe cam attachment part 64 as illustrated in FIGS. 15 to 17.

A cam groove 61 a is formed around the outer circumferential part of thecam forming part 61.

A slide groove 62 a that stretches in the circumferential direction isformed in the work part 62. The slide groove 62 a has one end edgeformed as a first regulation edge 62 b and the other end edge formed asa second regulation edge 62 c. A slide ring 66 is externally fitted toand supported by the work part 62 to be freely rotatable. A screw hole66 a is formed to penetrate the slide ring 66 in the radial direction.

A stopper screw 67 is assembled with the slide ring 66. The stopperscrew 67 is constituted by a head 67 a, a screw shaft 67 b, and a slideshaft 67 c, and the slide shaft 67 c protrudes from the screw shaft 67 bin the direction opposite to the head 67 a, and thus has a diameter alittle bit smaller than the screw shaft 67 b. The stopper screw 67 isassembled with the slide ring 66 as the screw shaft 67 b is screwed intothe screw hole 66 a. In the state in which the stopper screw 67 isassembled with the slide ring 66, the head 67 a is positioned on theouter circumference side of the slide ring 66, and the slide shaft 67 cis positioned on the inner circumference side of the slide ring 66(refer to FIG. 18). The stopper screw 67 is engaged to be freelyslidable when the slide shaft 67 c is inserted into the slide groove 62a of the work part 62.

A gear member 68 is externally fitted and fixed to the gear mountingpart 64 of the driving cam 60 (refer to FIG. 15). The gear member 68meshes with the intermediate gear 59 a of the gear body 59. Thus, adriving force of the driving motor 56 is transmitted to the gear member68 from the feeding gear 58 a via the intermediate gear 59 a, and thedriving cam 60 integrated with the gear member 68 in a directionaccording to a rotation direction of the driving motor 56 is rotated inthe axial rotation direction.

Bearing members 69 and 69 are mounted inside the intermediate supporthousing 29, separately from each other on the front and rear sides(refer to FIG. 8). The front supported shaft part 63 and the rearsupported shaft part 65 of the driving cam 60 are supported by thebearing members 69 and 69 to be freely rotatable, and disposed insidethe intermediate support housing 29.

A stopper base 70 is mounted in the intermediate support housing 29above the driving cam 60 (refer to FIGS. 8 and 19). The stopper base 70has a cover part 70 a that covers the driving cam 60 stretching forwardand rearward from above and a regulation pin 70 b that protrudesdownward from the cover part 70 a. The regulation pin 70 b is positionedabove the slide ring 66 supported by the driving cam 60, and the leadingend thereof can come in contact with the head 67 a of the stopper screw67 assembled with the slide ring 66.

The cam pin 32 a of the first zoom lens holding frame 32 and the cam pin38 of the second zoom lens holding frame 34 are engaged with the camgroove 61 a of the driving cam 60 to be freely slidable. Thus, when thedriving cam 60 is rotated due to a driving force of the driving motor56, the cam pin 32 a and the cam pin 38 are sent in the front-reardirection in the direction according to the rotation direction of thedriving cam 60, and the first zoom lens holding frame 32, the secondlens groups 33 and 33 held by the first zoom lens holding frame 32, thesecond zoom lens holding frame 34, and the third lens groups 39 and 39held by the second zoom lens holding frame 34 are guided by the guidingshafts 31 and 31 and move in the front-rear direction (the optical axisdirection), and thereby zooming is performed.

As described above, the first zoom lens holding frame 32, the secondlens groups 33 and 33, the second zoom lens holding frame 34, and thethird lens groups 39 and 39 function as moving objects moved by thedriving motor 56.

The driving cam 60 is set to be rotatable from one rotation end to theother rotation end (refer to FIGS. 19 to 22).

In the state in which the driving cam 60 is positioned at one rotationend, the head 67 a of the stopper screw 67 assembled with the slide ring66 comes in contact with the regulation pin 70 b of the stopper base 70as illustrated in FIG. 19, and thus rotation of the driving cam 60 inone direction is regulated by the regulation pin 70 b. At this time, thefirst regulation edge 62 b of the slide groove 62 a formed in the workpart 62 of the driving cam 60 comes in contact with the slide shaft 67 cof the stopper screw 67. Thus, rotation of the driving cam 60 in onedirection is regulated by the stopper screw 67.

When a driving force of the driving motor 56 is transmitted to thedriving cam 60 in the state in which the driving cam 60 is positioned atone rotation end, the driving cam 60 is rotated with respect to theslide ring 66 (refer to FIG. 20). When the driving cam 60 is rotated,the first regulation edge 62 b is separated from the stopper screw 67,and the slide shaft 67 c of the stopper screw 67 moves along the slidegroove 62 a.

When the driving cam 60 is further rotated, the slide shaft 67 c of thestopper screw 67 is pressed by the second regulation edge 62 c of theslide groove 62 a, and thus the slide ring 66 and the stopper screw 67are integrated with the driving cam 60 and rotated, and the stopperscrew 67 is gradually separated from the regulation pin 70 b (refer toFIG. 21). At this time, the driving cam 60 is rotated one or more roundsfrom the one rotation end.

When the driving cam 60 is continuously rotated in integration with theslide ring 66 and the stopper screw 67, the head 67 a of the stopperscrew 67 that has been pressed by the second regulation edge 62 c comesin contact with the regulation pin 70 b (refer to FIG. 22), therebyregulating the rotation of the driving cam 60, and reaches the otherrotation end. At this time, the driving cam 60 has been rotated abouttwo rounds from the one rotation end.

On the other hand, when the driving cam 60 is rotated in the state inwhich the driving cam 60 is positioned at the other rotation end, thesecond regulation edge 62 c is separated from the stopper screw 67 andthe slide shaft 67 c moves with respect to the slide groove 62 a. Whenthe driving cam 60 is further rotated, the slide shaft 67 c is pressedby the first regulation edge 62 b, the slide ring 66 and the stopperscrew 67 are integrated with the driving cam 60 and rotated, and therebythe head 67 a of the stopper screw 67 pressed by the first regulationedge 62 b is brought into contact with the regulation pin 70 b, therotation of the driving cam 60 is regulated, and the driving cam reachesthe one rotation end. At this time, the driving cam 60 has been rotatedabout two rounds from the other rotation end.

Since the slide ring 66 assembled with the stopper screw 67 is supportedby the driving cam 60 as described above, the driving cam 60 can berotated more than one round even in the configuration in which rotationof the driving cam 60 is regulated. Thus, a large amount of rotation ofthe driving cam 60 is secured after the rotation of the driving cam 60is regulated, an amount of movement of the second lens groups 33 and 33and the third lens groups 39 and 39 which are zoom lens groups in theoptical axis direction is increased, and thereby the variablemagnification function can be improved.

In addition, since the large amount of rotation of the driving cam 60can be secured, the amount of movement of the second lens groups 33 and33 and the third lens groups 39 and 39 in the optical axis direction canbe increased without lengthening the driving cam 60, and thusminiaturization of the medical observation device 1 in the optical axisdirection can be achieved.

Note that the example in which the driving cam 60 is rotated first withrespect to the slide ring 66, the stopper screw 67 is then pressed by apart of the driving cam 60, and the slide ring 66 and the stopper screw67 are integrated with the driving cam 60 and rotated has been describedabove. However, a configuration in which, when rotation of the drivingcam 60 is started in the medical observation device 1, the driving cam60 and the slide ring 66 are integrated and rotated first, the head 67 aof the stopper screw 67 is brought into contact with the regulation pin70 b to stop the rotation of the slide ring 66, and then the driving cam60 is continuously rotated with respect to the slide ring 66 is alsopossible.

A gear box 71 is mounted on one side of the rear end part of theintermediate support housing 29 (refer to FIG. 4). The gear box 71 has agear case 72 that opens sideward and upward and a gear cover 73 thatcloses the openings of the gear case 72 (refer to FIGS. 4, 23, 24 and25).

A holding protrusion part 74 that protrudes inward is provided on aninner face of the gear case 72 (refer to FIG. 26). The holdingprotrusion part 74 is formed with a plane part 74 a facing upward, afirst holding engagement part 74 b that is connected to one end of theplane part 74 a in the left-right direction and displaced furtherdownward as it runs deeper into the gear case 72, and a second holdingengagement part 74 c that is connected to the other end of the planepart 74 a in the left-right direction and displaced further downward asit runs further into an opening side of the gear case 72.

A manipulation hole 72 a is formed in a lower end part of the gear case72 (refer to FIG. 25). A detection switch 75 is mounted in the bottom ofthe gear case 72, and thus the detection switch 75 is positioned nearthe manipulation hole 72 a. The detection switch 75 has a switch piece75 a, and the switch piece 75 a is positioned across the manipulationhole 72 a.

A knob insertion hole 73 a that is penetrated to the left and right isformed in the gear cover 73 (refer to FIG. 26). The opening edge of theknob insertion hole 73 a is provided in the gear cover 73 as aflange-shaped movement regulation part 73 b jutting out on the innercircumference side.

A fulcrum shaft 76 is mounted on a surface of a deep side of the gearcase 72 in the left-right direction. The fulcrum shaft 76 has one endstretching in the left-right direction mounted on the surface of thedeep side of the gear case 72.

The fulcrum shaft 76 supports a manipulation object 77. An O-ring 78 ismounted at a position near one end of the fulcrum shaft 76.

The manipulation object 77 has a supported gear 79 and a manualmanipulation knob 80 mounted in one end of the supported gear 79.

The supported gear 79 includes a connection shaft 79 a that is supportedby the fulcrum shaft 76 and stretches in the left-right direction,integrated with a switch gear 79 b jutting outward from an end of theconnection shaft 79 a in the axial direction.

The manipulation object 77 can rotate with respect to the fulcrum shaft76 in the axial rotation direction of the fulcrum shaft 76, and can movewith respect to the fulcrum shaft 76 in the axial direction of thefulcrum shaft 76.

The manual manipulation knob 80 has a knob base 81 mounted on thesupported gear 79, and a manipulation cap 82 that is mounted on the knobbase 81 and covers the knob base 81 from the outside. At least a part ofthe manual manipulation knob 80 protrudes sideward from one insertionhole formed in the outer circumference part 8 of the outer housing 2(refer to FIG. 2).

The knob base 81 has a mounted part 81 a mounted by being screwed intothe supported gear 79 or the like, covering substantially a half of thesupported gear 79, and a flange-shaped regulated part 81 b juttingoutward from an end of the mounted part 81 a in the axial direction(refer to FIG. 26).

The manipulation cap 82 is mounted on the knob base 81, covering themounted part 81 a. In the state in which the manipulation cap 82 ismounted on the knob base 81, the outer circumference part of theregulated part 81 b is positioned on the outer side of the outercircumferential face of the manipulation cap 82. The outercircumferential face of the manipulation cap 82 is formed as a knobsurface 82 a processed in a predetermined shape through knurlingprocessing or the like. The manipulation object 77 is manually rotatedas the knob surface 82 a of the manipulation cap 82 is gripped. Thus, byforming the knob surface 82 a processed through knurling processing orthe like in the manipulation cap 82, a satisfactory manipulationproperty of the manipulation object 77 can be ensured.

The manual manipulation knob 80 can move between a first position thatis a movement end of the direction in which it is accommodated in thegear box 71 and a second position that is a movement end of thedirection in which it is drawn out from the gear box 71. In addition,the supported gear 79 is integrated with the knob base 81 and themanipulation cap 82 and moved, and the switch gear 79 b is moved to anon-meshing position when the manual manipulation knob 80 is moved tothe first position, and moved to a meshing position when the manualmanipulation knob 80 is moved to the second position.

A holding member 83 is supported by the supported gear 79 of themanipulation object 77 in an externally fitted manner. The holdingmember 83 can rotate with respect to the supported gear 79 in thedirection around the axis but is not able to move in the axial rotationdirection of the supported gear 79, and thus does not rotate along withthe supported gear 79 according to rotation in the axial rotationdirection of the manipulation object 77, but moves integrally with thesupported gear 79 according to movement in the axial direction of themanipulation object 77.

The holding member 83 has a tubular part 84 supported by the supportedgear 79 in an externally fitted manner and a connection protrusion part85 that protrudes from the tubular part 84 in the radial direction(outward). A manipulation protrusion part 84 a that protrudes outward isprovided in the tubular part (refer to FIG. 25). The leading end part ofthe manipulation protrusion part 84 a inserted into the manipulationhole 72 a formed in the gear case 72 protrudes outward from themanipulation hole 72 a. A convex position holding part 85 a is providedon an outer side of the connection protrusion part 85, and the positionholding part 85 a can be elastically deformed in a direction in which itis separated from or comes in contact with the tubular part 84 (refer toFIG. 26).

The manipulation object 77 configured as described above is configuredsuch that the manual manipulation knob 80 is inserted into the knobinsertion hole 73 a of the gear cover 73 and a part thereof on themanual manipulation knob 80 side is positioned outside the gear box 71.The regulated part 81 b of the knob base 81 is in a state in which it ispositioned inside the gear box 71 and thus can come in contact with themovement regulation part 73 b provided in the gear cover 73.

The transmission gear 86 is supported inside the gear box 71 to befreely rotatable. The transmission gear 86 has a gear shaft 87 thatstretches in the left-right direction and a movement gear 88 that isrotated using the gear shaft 87 as a fulcrum.

An end of the gear shaft 87 in the axial direction is mounted on thesurface on the deep side of the gear case 72 in the left-rightdirection, and the other end thereof in the axial direction is mountedon a part of the gear cover 73. A flange-shaped reception protrusionpart 87 a jutting outward from an intermediate part of the gear shaft 87in the axial direction is provided.

A flange-shaped reception part 88 a jutting inward is provided at oneend of the movement gear 88 in the axial direction. The movement gear 88can rotate with respect to the gear shaft 87 in the axial direction ofthe gear shaft 87. Thus, a movement space 71 a that allows movement ofthe movement gear 88 in the axial direction of the gear shaft 87 isformed inside the gear box 71.

A meshing assisting spring 89 that is a compression coil spring isdisposed in a center hole 88 b of the movement gear 88, and the meshingassisting spring 89 is disposed in a compressed state between thereception protrusion part 87 a of the gear shaft 87 and the receptionpart 88 a of the movement gear 88. Thus, the meshing assisting spring 89applies an urging force to the movement gear 88 in the directionopposite to the gear cover 73.

A plurality of interlocked gears 90, 90, . . . are supported to befreely rotatable inside the gear box 71 (refer to FIGS. 23 and 24). Theinterlocked gears 90, 90, . . . have a function of transmitting adriving force manually produced when the manipulation cap 82 ismanipulated along with the transmission gear 86 to the driving cam 60,and at least some of them function also as deceleration gears. Theinterlocked gear 90 positioned closest to the transmission gear 86meshes with the movement gear 88, and the interlocked gear 90 positionedclosest to the driving cam 60 meshes with the gear member 68 mounted inthe driving cam 60.

In the state in which the manual manipulation knob 80 is at the firstposition and the switch gear 79 b of the supported gear 79 is at thenon-meshing position, the switch gear 79 b does not mesh with themovement gear 88 as illustrated in FIG. 26. At this moment, the positionholding part 85 a of the holding member 83 meshes with a first holdingengagement part 74 b provided in the gear case 72 to cause themanipulation object 77 to be positioned with respect to the gear box 71,and thus the manual manipulation knob 80 is held at the first position,and the switch gear 79 b is held at the non-meshing position.

The driving cam 60 is rotated by a driving force of the driving motor 56when the switch gear 79 b is at the non-meshing position, the secondlens groups 33 and 33 and the third lens groups 39 and 39 are moved byelectromotive driving, and thus zooming is performed. At this moment,the switch gear 79 b does not mesh with the movement gear 88, and thus adriving force of the driving motor 56 is not transmitted to the switchgear 79 b, and therefore the manipulation object 77 is not rotated.

On the other hand, when it is not possible to perform electromotivedriving because the driving motor 56 has a problem or the like, theoperator 700 or the like grips the manipulation cap 82 to move themanipulation object 77 in the direction in which it is drawn out fromthe gear box 71, and thus manual zooming can be performed as follows.

When the manipulation cap 82 is gripped to move the manipulation object77 in the direction in which it is drawn out from the gear box 71, theswitch gear 79 b reaches the meshing position and thus meshes with themovement gear 88 (refer to FIG. 27). At this moment, the positionholding part 85 a of the holding member 83 is elastically deformedduring its movement, and then elastically restored after it moves ontothe plane part 74 a from the first holding engagement part 74 b, andmeshes with the second holding engagement part 74 c. Thus, themanipulation object 77 is positioned with respect to the gear box 71such that the manual manipulation knob 80 is held at the secondposition, and the switch gear 79 b is held at the meshing position.

When the manual manipulation knob 80 is moved from the first position tothe second position, the holding member 83 is moved according to themovement of the manipulation object 77, and the switch piece 75 a of thedetection switch 75 is manipulated by the manipulation protrusion part84 a. When the switch piece 75 a is manipulated, the driving motor 56 isin a non-driving state in which driving is not performed.

In addition, when the manual manipulation knob 80 is moved toward thesecond position from the first position, the regulated part 81 b can bebrought into contact with the movement regulation part 73 b, and thusmovement of the manual manipulation knob 80 with respect to the gear box71 is regulated when the regulated part 81 b is brought into contactwith the movement regulation part 73 b.

When the position holding part 85 a of the holding member 83 is engagedwith the second holding engagement part 74 c from the plane part 74 a, afeeling of a change in an engagement position is transmitted to the handin which the manipulation cap 82 is gripped, and thus the operator 700or the like experiences a so-called click feeling.

Thus, the engagement state of the position holding part 85 a with thesecond holding engagement part 74 c is recognized due to the size of aload transmitted to the manipulation cap 82 via the holding member 83during the movement of the manual manipulation knob 80, the operator 700or the like can easily recognize that a draw-out manipulation of themanipulation object 77 has been completed, and thus the draw-outmanipulation of the manipulation object 77 can be easily and reliablyperformed and the switch gear 79 b can be reliably moved to the meshingposition.

When the manual manipulation knob 80 is rotated in the state in whichthe knob surface 82 a of the manipulation cap 82 is gripped after thedraw-out manipulation of the manipulation object 77 is completed, adriving force generated through manual manipulation is transmitted fromthe switch gear 79 b to the driving cam 60 via the transmission gear 86,the interlocked gears 90, 90, . . . , and the gear member 68, the secondlens groups 33 and 33 and the third lens groups 39 and 39 are moved dueto the manual operation, and thus zooming is performed. Thus, thetransmission gear 86, the interlocked gears 90, 90, . . . , the gearmember 68, and the driving cam 60 function as a driving forcetransmission mechanism that transmits driving forces to the first zoomlens holding frame 32, the second lens groups 33 and 33, the second zoomlens holding frame 34, and the third lens groups 39 and 39 that functionas a moving object.

At this movement, the driving motor 56 is rotated according to therotation of the driving cam 60, and thus a load caused by the rotationof the driving motor 56 is exerted on the operator 700 or the like.Thus, it is desirable to use a component that has a torque that causesan optimum load exerted on the operator 700 during manipulation of themanual manipulation knob 80 as the driving motor 56.

Note that, when the draw-out manipulation of the manipulation object 77is performed, there is a possibility of an end face of the switch gear79 b coming in contact with an end face of the movement gear 88 when themanipulation object 77 is moved, resulting in the switch gear 79 b notmeshing with the movement gear 88, according to a phase of the gearteeth of the switch gear 79 b and a phase of the gear teeth of themovement gear 88. In this case, the movement gear 88 is pressed by theswitch gear 79 b according to movement of the supported gear 79, themovement gear 88 is moved in the movement space 71 a according to themovement of the supported gear 79 (refer to FIG. 28).

When the movement gear 88 is moved in the movement space 71 a, themeshing assisting spring 89 disposed in the center hole 88 b of themovement gear 88 is compressed, and thus an urging force of the meshingassisting spring 89 exerted on the movement gear 88 in the directionopposite to the gear cover 73 increases.

When the manual manipulation knob 80 is rotated in the state in whichthe movement gear 88 is moved according to the movement of the supportedgear 79, the supported gear 79 is rotated with respect to the movementgear 88 along with the manual manipulation knob 80, the phase of thegear teeth of the switch gear 79 b and the phase of the gear teeth ofthe movement gear 88 are thus in a different state from the previousphases, the movement gear 88 is moved in the direction opposite to thegear cover 73 due to the urging force of the meshing assisting spring89, and thereby the switch gear 79 b meshes with the movement gear 88.Then, zooming is performed by manually manipulating the manualmanipulation knob 80 to continuously rotate and thus the second lensgroups 33 and 33 and the third lens groups 39 and 39 to move.

As described above, since the medical observation device 1 has themeshing assisting spring 89 which urges the transmission gear 86 in adirection to bring it close to the switch gear 79 b in the axialdirection, even when the manual manipulation knob 80 is moved from thefirst position to the second position and thus the transmission gear 86is pressed and moved by the switch gear 79 b, the meshing assistingspring 89 causes the transmission gear 86 to move in the direction toget close to the switch gear 79 b through the rotation manipulation ofthe manual manipulation knob 80, and then the gears mesh with eachother.

Therefore, even when the switch gear 79 b and the transmission gear 86do not mesh with each other when the manual manipulation knob 80 movesfrom the first position to the second position, it is possible to causethe components to reliably mesh with each other, and thereby enhancereliability in operations.

Meanwhile, when the manipulation cap 82 is pressed into the gear box 71side in the state in which the manual manipulation knob 80 is drawn outfrom the gear box 71 and thus is at the second position, themanipulation object 77 is moved in the direction in which it isaccommodated in the gear box 71.

When the manipulation object 77 is moved in the direction in which it isaccommodated in the gear box 71, the position holding part 85 a of theholding member 83 is elastically deformed during the movement,elastically restored after it moves onto the plane part 74 a from thesecond holding engagement part 74 c, and meshes with the first holdingengagement part 74 b. Thus, the manipulation object 77 is positionedwith respect to the gear box 71 such that the manual manipulation knob80 is held at the second position, and the switch gear 79 b is held atthe non-meshing position.

When the manual manipulation knob 80 is moved from the second positionto the first position, the holding member 83 is moved according to themovement of the manipulation object 77, and the switch piece 75 a of thedetection switch 75 is manipulated by the manipulation protrusion part84 a. When the switch piece 75 a is manipulated, the driving motor 56 isin a driving state in which driving is possible.

When the position holding part 85 a of the holding member 83 is engagedwith the first holding engagement part 74 b from the plane part 74 a, afeeling of a change in an engagement position is transmitted to the handin which the manipulation cap 82 is gripped, and thus the operator 700or the like experiences a so-called click feeling.

Thus, the engagement state of the position holding part 85 a with thefirst holding engagement part 74 b is recognized due to the size of aload transmitted to the manipulation cap 82 via the holding member 83during the movement of the manual manipulation knob 80, the operator 700or the like can easily recognize that the pressing manipulation of themanipulation object 77 has been completed, and thus the pressingmanipulation of the manipulation object 77 can be easily and reliablyperformed and the switch gear 79 b can be reliably moved to thenon-meshing position.

In addition, in the medical observation device 1, the manualmanipulation knob 80 which can be manipulated to rotate in the axialrotation direction of the fulcrum shaft 76 and can be moved between thefirst position and the second position is provided, meshing of theswitch gear 79 b and the transmission gear 86 is released at thenon-meshing position, and the switch gear 79 b and the transmission gear86 mesh with each other at the meshing position.

Therefore, even in a state in which the manual manipulation knob 80 isnot rotated during electromotive driving using the driving motor 56 andelectromotive driving of the second lens groups 33 and 33 and the thirdlens groups 39 and 39 serving as moving objects is not possible, themoving objects can be moved through manual manipulation and it ispossible to prevent inconvenience from occurring during medicalprocedures, without causing them to be entwined with the protectionsheet 300 known as a drape during the electromotive driving.

Furthermore, when the switch gear 79 b is moved to the meshing position,the driving motor 56 is set to be in a non-driving state, it is possibleto prevent obstruction of manual manipulation to rotate the manualmanipulation knob 80 when the manual manipulation knob 80 is manipulatedto rotate, without causing the transmission gear 86 to rotate due todriving of the driving motor 56.

Furthermore, the direction from the first position to the secondposition is set as the direction in which the manual manipulation knob80 is drawn out from the gear box 71.

Thus, the manual manipulation knob 80 is manually manipulated in thestate in which the manual manipulation knob 80 has been drawn out fromthe gear box 71, the area of a portion of the manual manipulation knob80 gripped by fingers becomes large, and thus it is possible to ensure asatisfactory manipulation property of the manual manipulation knob 80.

In addition, in the medical observation device 1, when the manualmanipulation knob 80 is moved to the first position, the positionholding part 85 a of the holding member 83 is engaged with the firstholding engagement part 74 b of the gear box 71 and thus the switch gear79 b is held at the non-meshing position, and when the manualmanipulation knob 80 is moved to the second position, the positionholding part 85 a is engaged with the second holding engagement part 74c and thus the switch gear 79 b is held at the meshing position.

Thus, since the first holding engagement part 74 b and the secondholding engagement part 74 c are provided in the gear box 71, the gearbox 71 has the function of disposing each gear such as the switch gear79 b or the transmission gear 86 and the function of holding the switchgear 79 b at the meshing position and the non-meshing position, andtherefore the switch gear 79 b can be reliably held at the meshingposition and the non-meshing position without causing an increase in thenumber of components.

In addition, the movement regulation part 73 b is provided in the gearbox 71, and the regulated part 81 b that can be brought into contactwith the movement regulation part 73 b is provided in the manualmanipulation knob 80.

Thus, movement of the manual manipulation knob 80 with respect to thegear box 71 is regulated if the regulated part 81 b is brought intocontact with the movement regulation part 73 b when the manualmanipulation knob 80 is moved from the first position to the secondposition, which leads to regulation of more movement of the manualmanipulation knob 80 than necessary, and thus exfoliation of the manualmanipulation knob 80 from the gear box 71 can be prevented.

Note that, since the medical observation device 1 is covered by theprotection sheet 300 when used during medical procedures, the manualmanipulation knob 80 may be manually manipulated to rotate from theoutside of the protection sheet 300 in the state in which the protectionsheet 300 overlaps the manual manipulation knob 80 and thus they aregripped together.

Therefore, in order to ensure a satisfactory manipulation property, aconfiguration in which, for example, a manipulation mechanism having amanipulation unit with which manual manipulation can be performed at adifferent position from the manual manipulation knob 80 is connected tothe manual manipulation knob 80, and the manual manipulation knob 80 isrotated by manually manipulating the manipulation unit is possible.

<Configuration of Rear Barrel Section>

Next, a configuration of the rear barrel section 13 will be described(with reference to FIGS. 3, 4, and 5, and FIGS. 29 to 55).

The rear barrel section 13 has a rear support housing 91 and respectivenecessary parts mounted or supported inside and outside of the rearsupport housing 91 (refer to FIGS. 3 to 5). The rear barrel section 13is disposed inside the main body 3 of the outer housing 2 excluding atleast a part of a manipulation lever to be described below.

The rear support housing 91 has a box-shaped case body 92 that opensforward and a cover body 93 that closes the opening of the case body 92(refer to FIG. 29 to FIG. 31). The rear support housing 91 is mounted inthe rear face part 29 b of the intermediate support housing 29 frombehind using a fastening screw, or the like.

The case body 92 has an upper face part 94, a lower face part 95, a rearface part 96, a left side face part 97, and a right side face part 98,and is formed in a shape that extends horizontally with the width in theleft-right direction slightly longer than the width in the upper-lowerdirection (refer to FIGS. 32 to 34).

Lens frame parts 96 a and 96 a formed in a circular frame shape areprovided on the left and right in the front face of the rear face part96. The rear face part 96 has upper and lower end parts positionedfurther backward than parts other than the upper and lower end parts,and a shallow concave part 96 b that opens rearward is formed in theparts other than the upper and lower end parts (refer to FIG. 35).Disposition frame parts 96 c and 96 c formed in a rectangular shape thatextends horizontally are provided on the left and right on the rear faceside of the rear face part 96. Rectangular incidence windows 96 d and 96d are formed on the inner side of the disposition frame parts 96 c and96 c in the rear face part 96.

First stopper parts 96 e and 96 e are provided at positions near theupper end of the front face (inner face) of the rear face part 96, andsecond stopper parts 96 f and 96 f are provided at positions near thelower end thereof (refer to FIG. 34). The first stopper parts 96 e and96 e and the second stopper parts 96 f and 96 f are positionedseparately from each other on the left and right sides and protrudeslightly forward.

A lever support hole 97 a is formed in the left side face part 97 (referto FIG. 32). A spring hook protrusion 97 b and a support shaft 97 c thatprotrude outward (sideward) are provided above the spring support hole97 a in the left side face part 97.

A cap support hole 98 a is formed in the right side face part 98 (referto FIG. 33). Terminal protrusion holes 98 b and 98 b are formedseparately from each other on the upper and lower sides on the frontside of the cap support hole 98 a in the right side face part 98.

Circular lens holding parts 93 a and 93 a are provided in the cover body93, separately from each other on the left and right sides (refer toFIGS. 29 and 31). Light transmissive holes 93 b and 93 b are formed onthe inner side of the lens holding parts 93 a and 93 a in the cover body93 (refer to FIG. 31). Fourth lens groups 99 and 99 are mounted in thelens holding parts 93 a and 93 a, and the fourth lens groups 99 and 99are set as fixed lens groups.

Fifth lens groups 100 and 100 are mounted in the lens frame parts 96 aand 96 a of the rear face part 96, and the fifth lens groups 100 and 100are set as fixed lens groups. Note that the fourth lens groups 99 and 99and the fifth lens groups 100 and 100 are all set as fixed lens groups,and the fifth lens groups 100 and 100 may constitute a part of thefourth lens groups. In this case, both the fourth lens groups 99 and 99and the fifth lens groups 100 and 100 function as one fourth lens group.

An element unit 102 is mounted in the rear face part 96 via seal members101 and 101 (refer to FIGS. 30 and 31).

The seal members 101 and 101 are disposed to be inserted into thedisposition frame parts 96 c and 96 c of the rear face part 96 (refer toFIG. 31). Each seal member 101 is formed of a material that can beelastically deformed, such as a rubber material, in a rectangular frameshape that extends horizontally.

The element unit 102 has an adaptor 103 formed in substantially a plateshape facing the front-rear direction, seal glass 104 and 104 disposedon the adaptor 103, and element modules 105 and 105 mounted on the sealglass 104 and 104 (refer to FIGS. 30 and 31).

The adaptor 103 is formed in a rectangular shape that extendssubstantially horizontally, disposed to be inserted into the concavepart 96 b of the rear face part 96, and mounted on the rear face part 96using a fastening screw or the like. Disposition concave parts 103 a and103 a that open rearward are formed on the left and right sides of theadaptor 103. Transmissive insertion holes 103 b and 103 b are formed onthe inner side of the disposition concave parts 103 a and 103 a on theadaptor 103.

The rear end parts of the seal members 101 and 101 are inserted into thetransmissive insertion holes 103 b and 103 b of the adaptor 103.

The seal glass 104 and 104 is disposed to be inserted into thedisposition concave parts 103 a and 103 a of the adaptor 103, and theirouter circumference parts are mounted on the adaptor 103 throughadhesion, or the like. In the state in which the seal glass 104 and 104is mounted on the adaptor 103, the outer circumference part of the sealglass 104 and 104 is pressed by the rear end part of the seal members101 and 101, the rear end part of the seal members 101 and 101 is thuselastically deformed to bend outward, and thereby the rear end part ofthe seal members 101 and 101 tightly adheres to the front face of theseal glass 104 and 104.

Thus, it is difficult for foreign substances such as dust to infiltratethe rear support housing 91 and foreign substances such as dust toadhere to the front face of the seal glass 104 and 104, and thereforequality of images or videos captured by the medical observation device 1can be improved.

The element module 105 is constituted of a base plate 105 a and an imagesensor 105 b, and is configured such that the image sensor 105 b isattached to the base plate 105 a. The image sensor 105 b has a functionof photoelectrically converting a subject image captured by an imagingoptical system. The front faces of the element modules 105 and 105 aremounted on the rear faces of the seal glass 104 and 104 in a tightcontact state, and have a greater area than the seal glass 104 and 104.

Since the concave part 96 b that opens rearward is formed in the rearface part 96 of the rear support housing 91 and the seal glass 104 and104 of the element unit 102 is disposed in the concave part 96 b asdescribed above, the rear barrel section 13 can be thin in the opticalaxis direction, and therefore the medical observation device 1 can beminimized.

A manipulation lever 106 is supported on the left side face part 97 tobe freely rotatable (refer to FIGS. 3, 29 and 31). The manipulationlever 106 integrates a plate-shaped rotation plate part 107 facing inthe left-right direction, a manipulation protrusion part 108 thatprotrudes outward (sideward) from the outer face of the rotation platepart 107, and a cylindrical part 109 that protrudes inward (sideward)from the inner face of the rotation plate part 107 as illustrated inFIGS. 29 and 36.

A first engagement concave part 107 a, a second engagement concave part107 b, and a third engagement concave part 107 c are formed from thefront side in order in the outer circumference part of the rotationplate part 107, separately from each other in the circumferentialdirection. A screw insertion hole 107 d is formed at substantially thecenter of the rotation plate part 107.

The manipulation protrusion part 108 is linearly formed, and its centerin the longitudinal direction is positioned near the screw insertionhole 107 d.

The cylindrical part 109 is provided around the screw insertion hole 107d in a substantially cylindrical shape. Positioning notches 109 a and109 a that open to the front end side are formed in the cylindrical part109, and the positioning notches 109 a and 109 a are positioned oppositeto each other by 180°.

The cylindrical part 109 is inserted into the lever support hole 97 a,and thus the manipulation lever 106 is supported on the left side facepart 97 to be freely rotatable. At least a part of the manipulationlever 106 protrudes from the other insertion hole formed in the outercircumference part 8 of the outer housing 2 to a side.

Since at least a part of the manipulation lever 106 protrudes from theinsertion hole of the outer housing 2 to the side as described above, itis possible to perform manual rotation manipulation of the manipulationlever 106 from the outside of the protection sheet 300. Manipulation ofthe manipulation lever 106 from the outside of the protection sheet 300can be performed in the state in which the protection sheet 300 overlapsthe manipulation lever 106 and thus they are gripped together.

In addition, in order to secure a satisfactory manipulation property ofthe manipulation lever 106 like the manual manipulation knob 80described above, a configuration in which the manipulation lever 106 isrotated by, for example, connecting a manipulation mechanism having amanipulation unit with which manual manipulation can be performed at adifferent position from the manipulation lever 106 to the manipulationlever 106, and manually manipulating the manipulation unit is possible.

A click lever 110 is supported by the support shaft 97 c on the leftside face part 97 to be freely turnable (refer to FIGS. 3, 29, and 31).The click lever 110 has a cylindrical shaft-shaped part 110 a of whichthe axial direction is set to the left-right direction, a plate-shapedconnection plate part 110 b of which one end continues from theshaft-shaped part 110 a, facing the left-right direction, and aplate-like engagement protrusion part 110 c that is positioned on theouter side (left side) of the connection plate part 110 b, facing theleft-right direction, as illustrated in FIGS. 29 and 37. A springsupport protrusion part 110 d that protrudes inward (to the right side)from the connection plate part 110 b is provided in the click lever 110.

The click lever 110 is supported on the left side face part 97 to befreely turnable using the support shaft 97 c as the fulcrum because thesupport shaft 97 c is inserted into the shaft-shaped part 110 a. Theclick lever 110 is supported on the left side face part 97 by insertinga shoulder screw 150 into the shaft-shaped part 110 a to be screwed intothe support shaft 97 c.

In the state in which the click lever 110 is supported on the left sideface part 97, an urging spring 111 is supported between the left sideface part 97 and the click lever 110. The urging spring 111 is, forexample, a toggle spring, one end 111 a of which is supported by thespring hook protrusion 97 b of the left side face part 97, and the otherend 111 b of which is supported by the spring support protrusion part110 d of the click lever 110.

The click lever 110 is positioned on an upper side of the manipulationlever 106, and the engagement protrusion part 110 c presses the outercircumferential face of the manipulation lever 106 from above using anurging force of the urging spring 111.

A cylindrical cap 112 is supported on the right side face part 98 to befreely rotatable (refer to FIG. 31). The cylindrical cap 112 integratesan insertion cylinder part 113 formed in a substantially cylindricalshape and a flange-like exfoliation regulation part 114 jutting outwardfrom one end of the insertion cylinder part 113 in the axial direction,as illustrated in FIGS. 31 and 38. Positioning notches 113 a and 113 athat open to the opposite side to the exfoliation regulation part 114are formed in the insertion cylinder part 113, and the positioningnotches 113 a and 113 a are positioned opposite to each other by 180°.

The cylindrical cap 112 is supported on the right side face part 98 tobe freely rotatable as the insertion cylinder part 113 is inserted intothe cap support hole 98 a.

A first position detection sensor 115 and a second position detectionsensor 116 are mounted on the right side face part 98 (refer to FIG.30). As the first position detection sensor 115 and the second positiondetection sensor 116, for example, a photointerrupter which performsoptical detection is used.

The first position detection sensor 115 has a pair of detectors 115 aand 115 a and terminals 115 b and 115 b, the detectors 115 a and 115 aare positioned on an inner face side of the right side face part 98, andthe terminals 115 b and 115 b protrude on an outer face side of theright side face part 98 from one terminal protrusion hole 98 b. Thefirst position detection sensor 115 is connected to a detection circuitthat is not illustrated via the terminals 115 b and 115 b.

The second position detection sensor 116 has a pair of detectors 116 aand 116 a and terminals 116 b and 116 b, the detectors 116 a and 116 aare positioned on the inner face side of the right side face part 98,and the terminals 116 b and 116 b protrude on the outer face side of theright side face part 98 from the other terminal protrusion hole 98 b.The second position detection sensor 116 is connected to a detectioncircuit that is not illustrated via the terminals 116 b and 116 b.

The first position detection sensor 115 and the second positiondetection sensor 116 are positioned separately from each other in thecircumferential direction in which the cap support hole 98 a serves as afulcrum.

In the state in which the cylindrical cap 112 is supported and the firstposition detection sensor 115 and the second position detection sensor116 are mounted on the right side face part 98, a side face cover 117 ismounted on an outer face of the right side face part 98 (refer to FIG.4). Thus, the cylindrical cap 112, the terminals 115 b and 115 b of thefirst position detection sensor 115, and the terminals 116 b and 116 bof the second position detection sensor 116 are covered and protected bythe side face cover 117.

The element holding frame 118 is supported inside the rear supporthousing 91 to be freely turnable (refer to FIG. 31). The element holdingframe 118 has an element holding part 119, a left wall 120, a right wall121, a divider 122, and a light shielding wall 123 (refer to FIGS. 39 to41).

The element holding part 119 has an intermediate frame part 124, aone-end frame part 125, and an other-end frame part 126, all of whichare formed in rectangular shapes that extend horizontally. Theintermediate frame part 124, the one-end frame part 125, and theother-end frame part 126 are consecutively provided, the one-end framepart 125 is positioned on a lower side of the other-end frame part 126,and the intermediate frame part 124 is positioned between the one-endframe part 125 and the other-end frame part 126. The lower end part ofthe intermediate frame part 124 overlaps the upper end part of theone-end frame part 125, and the upper end part of the intermediate framepart 124 overlaps the lower end part of the other-end frame part 126.

Protruding first stopper-receiving parts 119 a and 119 a are provided onthe left and right end parts on the end face of the other-end frame part126 on the opposite side to the intermediate frame part 124 in theelement holding part 119 (refer to FIG. 40). Protruding secondstopper-receiving parts 119 b and 119 b are provided on the left andright end parts on the end face of the one-end frame part 125 on theopposite side to the intermediate frame part 124 in the element holdingpart 119 (refer to FIG. 41).

An angle A between the intermediate frame part 124 and the one-end framepart 125 is set to 135 degrees and an angle B between the intermediateframe part 124 and the other-end frame part 126 is set to 135 degreeswithin a vertical surface including the optical axis in the elementholding frame 118 as illustrated in FIG. 42. Thus, the angle between theone-end frame part 125 and the other-end frame part 126 within thevertical surface including the optical axis is set to 90 degrees, andthus the one-end frame part 125 and the other-end frame part 126 are ina vertical state.

The left wall 120 protrudes from the left end part of the elementholding part 119 in the direction orthogonal to the element holding part119 (refer to FIGS. 39 to 41). A fulcrum shaft 120 a whose axialdirection is set to the left-right direction is provided on the outerface in the leading end part of the left wall 120 (refer to FIGS. 39 and40). The fulcrum shaft 120 a is formed in a cylindrical shape that opensoutward. Positioning protrusion parts 120 b and 120 b that areconsecutive on the outer circumference of the fulcrum shaft 120 a areprovided on the left wall 120. The positioning protrusion parts 120 band 120 b are provided opposite to each other with the fulcrum shaft 120a therebetween.

The right wall 121 protrudes from the right end part of the elementholding part 119 in the direction orthogonal to the element holding part119 (refer to FIGS. 39 to 41). A fulcrum shaft 121 a whose axialdirection is set to the left-right direction is provided on the outerface in the leading end part of the right wall 121 (refer to FIG. 41).The fulcrum shaft 121 a is formed in a cylindrical shape that opensoutward. Positioning protrusion parts 121 b and 121 b that areconsecutive on the outer circumference of the fulcrum shaft 121 a areprovided on the right wall 121. The positioning protrusion parts 121 band 121 b are provided opposite to each other with the fulcrum shaft 121a therebetween.

A detection piece 121 c that protrudes outward is provided on the rightwall 121.

The divider 122 is positioned at the center of the element holding part119 in the left-right direction, and provided from the lower end part ofthe one-end frame part 125 to the upper end part of the other-end framepart 126 (refer to FIGS. 39 to 41). Thus, the respective inner spaces ofthe intermediate frame part 124, the one-end frame part 125, and theother-end frame part 126 of the element holding part 119 are dividedinto the left and right by the divider 122.

The light shielding wall 123 protrudes from the divider 122, and ispositioned parallel with the left wall 120 and the right wall 121.

The light shielding wall 123 has a function of, when light enters thefifth lens groups 100 and 100 held in the rear face part 96 of the casebody 92 from the fourth lens groups 99 and 99 held in the cover body 93,shielding some of the light and preventing it from entering the rightfifth lens group 100 from the left fourth lens group 99 or the leftfifth lens group 100 from the right fourth lens group 99.

Thus, the light shielding wall 123 can prevent unnecessary incidence oflight on the respective optical paths in the binocular optical system,and therefore quality of images and videos captured by the medicalobservation device 1 can be improved.

In addition, the light shielding wall 123 reinforces the element holdingframe 118, and thus strength of the element holding frame 118 isincreased.

A first optical element 127 is mounted and held in the intermediateframe part 124 of the element holding frame 118 from the front side ofthe divider 122 through adhesion or the like. The first optical element127 is an optical filter, and as the first optical element 127, forexample, an infrared cut-off filter is used.

A second optical element 128 is mounted and held in the one-end framepart 125 of the element holding frame 118 from the front side of thedivider 122 through adhesion or the like. The second optical element 128is an optical filter, and as the second optical element 128, forexample, a special light observation filter that allows only excitationwavelengths of fluorochrome to penetrate therethrough is used.

The second optical element 128 is used in, for example, photo dynamicdiagnosis (PDD) in the medical field. Photo dynamic diagnosis is adiagnosis method of observing a state of a tumor using a special lightobservation filter that allows only fluorescence that is excited whenlight having a specific wavelength is radiated thereto to penetratetherethrough when a photosensitive substance or fluorescent substancehas been administered into a body and specifically accumulates in excessin the tumor.

A third optical element 129 is mounted and held in the other-end framepart 126 of the element holding frame 118 from the front side of thedivider 122 through adhesion or the like. The third optical element 129is an optical filter, and as the third optical element 129, for example,a special light observation filter that allows only excitationwavelengths of fluorochrome to penetrate therethrough is used.

The third optical element 129 is used in, for example, indocyanine green(ICG) fluorescence imaging in the medical field. The ICG fluorescenceimaging is a method of observing a state of a blood vessel or the likeusing a special light observation filter that allows only fluorescencethat is excited when near infrared light of a specific wavelength areais radiated thereto to penetrate therethrough when ICG that is afluorescent substance has been administered into a body and bonded witha specific substance included in the blood.

The imaging optical system is provided in the medical observation device1 as a binocular optical system, and the first optical element 127, thesecond optical element 128, and the third optical element 129 arepositioned across the two optical axes of the binocular optical system.

As described above, the first optical element 127, the second opticalelement 128, and the third optical element 129 having wavelengthselectivity of allowing different wavelengths penetrate therethrough areused in the medical observation device 1.

Thus, types of captured images differ according to subjects (lesions),imaging can be performed according to applications, and thereforefunctionality of the medical observation device 1 can be improved.

In addition, the imaging optical system is provided in the medicalobservation device 1 as a binocular optical system, and the firstoptical element 127, the second optical element 128, and the thirdoptical element 129 are positioned across the two optical axes of thebinocular optical system.

Thus, since each of the first optical element 127, the second opticalelement 128, and the third optical element 129 is positioned to becompatible with a binocular optical system, the number of opticalelements may decrease accordingly, the number of components can thus bereduced, and therefore high functionality of the medical observationdevice 1 can be secured.

Note that, although the example in which the second optical element 128is used for PDD and the third optical element 129 is used for ICG hasbeen described above, conversely, the second optical element 128 may beused for ICG and the third optical element 129 may be used for PDD.

However, the first optical element 127 that is an infrared cut-offfilter is an optical element with the highest use frequency. Thus, inboth cases in which it is desired to use the first optical element 127after use of the second optical element 128 and to use the first opticalelement 127 after use of the third optical element 129, it is desirableto position the first optical element 127 between the second opticalelement 128 and the third optical element 129 so that the first opticalelement 127 can be quickly used when the element holding frame 118 isturned.

The element holding frame 118 is connected to the manipulation lever 106as a stepped screw 151 is inserted into the cylindrical part 109 of themanipulation lever 106 to be screwed into the fulcrum shaft 120 a of theleft wall 120 in the state in which the element holding frame 118 isinserted into the rear support housing 91 (refer to FIG. 31). At thismoment, the positioning protrusion parts 120 b and 120 b provided on theleft wall 120 of the element holding frame 118 are inserted into thepositioning notches 109 a and 109 a formed in the cylindrical part 109of the manipulation lever 106, and thus the manipulation lever 106 andthe element holding frame 118 are positioned, and rotation of theelement holding frame 118 with respect to the manipulation lever 106 isregulated. Thus, the manipulation lever 106 and the element holdingframe 118 are integrated and can turn together.

In addition, the element holding frame 118 is connected to thecylindrical cap 112 as a stepped screw 152 is inserted into theinsertion cylinder part 113 of the cylindrical cap 112 to be screwedinto the fulcrum shaft 121 a of the right wall 121 in the state in whichthe element holding frame 118 is inserted into the rear support housing91. At this moment, the positioning protrusion parts 121 b and 121 bprovided on the right wall 121 of the element holding frame 118 areinserted into the positioning notches 113 a and 113 a formed in theinsertion cylinder part 113 of the cylindrical cap 112, and thus thecylindrical cap 112 and the element holding frame 118 are positioned,and rotation of the element holding frame 118 with respect to thecylindrical cap 112 is regulated. Thus, the cylindrical cap 112 and theelement holding frame 118 are integrated with the manipulation lever 106and can turn together.

With the configuration described above, the element holding frame 118holding the first optical element 127, the second optical element 128,and the third optical element 129 is integrated with the manipulationlever 106 and the cylindrical cap 112 and can be turned with respect tothe rear support housing 91, and the axial direction of the turningshaft of the element holding frame 118, i.e., the direction in which thefulcrum shaft 120 a of the left wall 120 is connected with the fulcrumshaft 121 a of the right wall 121, is set as the direction orthogonal tothe optical axis direction (the left-right direction).

In the state in which the element holding frame 118 is turnable insidethe rear support housing 91, the element holding frame 118 is positionedbetween the fourth lens groups 99 and 99 and the fifth lens groups 100and 100, both of which are fixed lens groups, and the element holdingframe 118, the first optical element 127, the second optical element128, and the third optical element 129 are positioned between theportions in which the respective fixed lens groups are mounted in therear support housing 91.

Thus, respective portions of the element holding frame 118, the firstoptical element 127, the second optical element 128, and the thirdoptical element 129 are shielded by each part in which the fixed lensgroups are mounted in the optical axis direction, adhesion of foreignsubstances like dust to the first optical element 127, the secondoptical element 128, and the third optical element 129 can thus besuppressed, and therefore quality of images and videos captured by themedical observation device 1 can be improved.

Furthermore, since the rear support housing 91 is formed in a box shapehaving a space inside and the element holding frame 118 is positionedinside the rear support housing 91, the element holding frame 118, thefirst optical element 127, the second optical element 128, and the thirdoptical element 129 are tightly sealed by the rear support housing 91.

Therefore, adhesion of foreign substances like dust to the first opticalelement 127, the second optical element 128, and the third opticalelement 129 can be further suppressed, and quality of images and videoscaptured by the medical observation device 1 can be further improved.

A turning operation of the element holding frame 118 will be describedbelow (with reference to FIGS. 43 to 51).

The element holding frame 118 is turned between a first turning positionand a second turning position, the center position of the turning rangefrom the first turning position to the second turning position is set asan intermediate position, and the element holding frame 118 stops and isheld at any position of the first turning position, the intermediateposition, and the second turning position.

In a state in which the element holding frame 118 is at the intermediateposition, the first optical element 127 held in the intermediate framepart 124 of the element holding frame 118 is positioned on the opticalaxis to be orthogonal to the optical axis, facing the front-reardirection, as illustrated in FIGS. 43 and 44. Thus, light that haspenetrated the fourth lens groups 99 and 99 penetrates the first opticalelement 127 and then is incident on the fifth lens groups 100 and 100.

At this moment, the engagement protrusion part 110 c of the click lever110 is engaged with the second engagement concave part 107 b of themanipulation lever 106 (refer to FIG. 43), and the engagement protrusionpart 110 c is pressed by an urging force of the urging spring 111 fromabove the rotation plate part 107. Thus, since the manipulation lever106 is pressed by the engagement protrusion part 110 c, the elementholding frame 118 is held at the intermediate position.

At the intermediate position, the detection piece 121 c provided on theright wall 121 of the element holding frame 118 is positioned betweenfirst position detection sensor 115 and the second position detectionsensor 116 mounted on the right side face part 98 of the rear supporthousing 91 (refer to FIG. 45). Since the detection piece 121 c ispositioned between the first position detection sensor 115 and thesecond position detection sensor 116 and is present neither between thepair of detectors 115 a and 115 a nor between the pair of detectors 116a and 116 a, the element holding frame 118 is detected to be at theintermediate position.

If the manipulation lever 106 is manipulated to rotate to one side inthe state in which the element holding frame 118 is at the intermediateposition, the manipulation lever 106 rotates while the engagementprotrusion part 110 c of the click lever 110 is pressed to the outercircumferential face of the rotation plate part 107 by an urging forceof the urging spring 111, and the engagement protrusion part 110 c isengaged with the first engagement concave part 107 a (refer to FIGS. 46and 47). When the manipulation lever 106 is manually manipulated torotate, the operator 700 or the like can grip the manipulationprotrusion part 108 of the manipulation lever 106 to manipulate it, andthus the provision of the manipulation protrusion part 108 in themanipulation lever 106 can enable rotation manipulation of themanipulation lever 106 to be easily and reliably performed.

At this moment, turning of the element holding frame 118 is regulatedwhen the first stopper-receiving parts 119 a and 119 a run into thefirst stopper parts 96 e and 96 e provided in the rear face part 96 ofthe rear support housing 91, and thus turning to the first turningposition is performed (refer to FIG. 47). In the state in which theelement holding frame 118 is turned to the first turning position, theengagement protrusion part 110 c is pressed to the first engagementconcave part 107 a by an urging force of the urging spring 111 appliedin the direction in which the manipulation lever 106 is rotatedclockwise when viewed from the outside. Thus, the urging force of theurging spring 111 is transmitted to the element holding frame 118 viathe manipulation lever 106, the first stopper-receiving parts 119 a and119 a of the element holding frame 118 are pressed to the first stopperparts 96 e and 96 e, and then the element holding frame 118 is held atthe first turning position since the first stopper-receiving parts 119 aand 119 a are pressed to the first stopper parts 96 e and 96 e.

In the medical observation device 1 described above, the firststopper-receiving parts 119 a and 119 a are provided in the elementholding frame 118, and the first stopper parts 96 e and 96 e for holdingthe element holding frame 118 at the first turning position when thefirst stopper-receiving parts 119 a and 119 a are brought into contactwith the rear support housing 91 are provided.

Thus, no mechanism for holding the element holding frame 118 at thefirst turning position is necessary, and the element holding frame 118can be easily and reliably held at the first turning position withoutcausing an increase in manufacturing costs of the medical observationdevice 1.

In addition, the urging spring 111 that presses the firststopper-receiving parts 119 a and 119 a to the first stopper parts 96 eand 96 e is provided in the medical observation device 1.

Thus, since the first stopper-receiving parts 119 a and 119 a arepressed to the first stopper parts 96 e and 96 e by the urging force ofthe urging spring 111, the element holding frame 118 can be held at thefirst turning position in a stable state.

In the state in which the element holding frame 118 is turned to thefirst turning position, the second optical element 128 held in theone-end frame part 125 of the element holding frame 118 is positioned onthe optical axis to be orthogonal to the optical axis, facing thefront-rear direction as illustrated in FIGS. 46 and 47. Thus, light thathas penetrated the fourth lens groups 99 and 99 penetrates the secondoptical element 128 and then is incident on the fifth lens groups 100and 100.

At the first turning position, the detection piece 121 c provided on theright wall 121 of the element holding frame 118 is positioned betweenthe pair of detectors 115 a and 115 a of the first position detectionsensor 115 mounted on the right side face part 98 of the rear supporthousing 91 (refer to FIG. 48). Since the detection piece 121 c ispositioned between the pair of detectors 115 a and 115 a, it is detectedthat the element holding frame 118 is at the first turning position.

As described above, since the angle formed by the intermediate framepart 124 and the one-end frame part 125 and the angle formed by theintermediate frame part 124 and the other-end frame part 126 within thevertical plane including the optical axis are all set to 135 degrees andthe angle formed by the one-end frame part 125 and the other-end framepart 126 within the vertical plane including the optical axis is set to90 degrees, the other-end frame part 126 and the third optical element129 held in the other-end frame part 126 are parallel with the opticalaxis in the state in which the element holding frame 118 is held at thefirst turning position (refer to FIG. 47).

Thus, the other-end frame part 126 and the third optical element 129 donot protrude in the direction orthogonal to the optical axis, and thusminiaturization of the medical observation device 1 in the directionorthogonal to the optical axis can be achieved.

On the other hand, if the manipulation lever 106 is manipulated torotate to the other side in the state in which the element holding frame118 is at the intermediate position, the manipulation lever 106 isrotated while the engagement protrusion part 110 c of the click lever110 is pressed to the outer circumferential face of the rotation platepart 107 by an urging force of the urging spring 111, and the engagementprotrusion part 110 c is engaged with the third engagement concave part107 c (refer to FIGS. 49 and 50).

At this moment, turning of the element holding frame 118 is regulatedwhen the second stopper-receiving parts 119 b and 119 b run into thesecond stopper parts 96 f and 96 f provided in the rear face part 96 ofthe rear support housing 91, and thus turning to the second turningposition is performed (refer to FIG. 50). In the state in which theelement holding frame 118 is turned to the second turning position, theengagement protrusion part 110 c is pressed to the third engagementconcave part 107 c by an urging force of the urging spring 111 appliedin the direction in which the manipulation lever 106 is rotatedanticlockwise when viewed from the outside. Thus, the urging force ofthe urging spring 111 is transmitted to the element holding frame 118via the manipulation lever 106, the second stopper-receiving parts 119 band 119 b of the element holding frame 118 are pressed to the secondstopper parts 96 f and 96 f, and then the element holding frame 118 isheld at the second turning position since the second stopper-receivingparts 119 b and 119 b are pressed to the second stopper parts 96 f and96 f.

In the medical observation device 1 described above, the secondstopper-receiving parts 119 b and 119 b are provided in the elementholding frame 118, and the second stopper parts 96 f and 96 f forholding the element holding frame 118 at the second turning positionwhen the second stopper-receiving parts 119 b and 119 b are brought intocontact with the rear support housing 91 are provided.

Thus, no mechanism for holding the element holding frame 118 at thesecond turning position is necessary, and the element holding frame 118can be easily and reliably held at the second turning position withoutcausing an increase in manufacturing costs of the medical observationdevice 1.

In addition, the urging spring 111 that presses the secondstopper-receiving parts 119 b and 119 b to the second stopper parts 96 fand 96 f is provided.

Thus, since the second stopper-receiving parts 119 b and 119 b arepressed to the second stopper parts 96 f and 96 f by the urging force ofthe urging spring 111, the element holding frame 118 can be held at thesecond turning position in a stable state.

Furthermore, the urging spring 111 presses the first stopper-receivingparts 119 a and 119 a to the first stopper parts 96 e and 96 e at afirst turning end and presses the second stopper-receiving parts 119 band 119 b to the second stopper parts 96 f and 96 f at a second turningend.

Thus, since the first stopper-receiving parts 119 a and 119 a and thesecond stopper-receiving parts 119 b and 119 b are pressed respectivelyto the first stopper parts 96 e and 96 e and the second stopper parts 96f and 96 f by the urging force of the one urging spring 111, a reductionin the number of components of the medical observation device 1 andsimplification of the mechanism can be achieved, and further the elementholding frame 118 can be held at the first turning position and thesecond turning position in stable states.

Note that the medical observation device 1 may also be configuredwithout providing the first stopper-receiving parts 119 a and 119 a, thesecond stopper-receiving parts 119 b and 119 b, the first stopper parts96 e and 96 e, and the second stopper parts 96 f and 96 f, and with theengagement protrusion part 110 c of the click lever 110 engaged with thefirst engagement concave part 107 a of the manipulation lever 106 tocause the element holding frame 118 to be held at the first turningposition, and the engagement protrusion part 110 c of the click lever110 engaged with the third engagement concave part 107 c of themanipulation lever 106 to cause the element holding frame 118 to be heldat the second turning position.

Furthermore, the medical observation device 1 is configured such thatthe urging force of the urging spring 111 is applied to the elementholding frame 118 via the manipulation lever 106 as described above.

Thus, the manipulation lever 106 functions as a power transmission meansthat applies a turning force to the element holding frame 118 and as anurging force transmission means that applies an urging force to theelement holding frame 118, and thus power and an urging force can bereliably applied to the element holding frame 118, in addition toachievement of a reduction in the number of components of the medicalobservation device 1 and simplification of the mechanism.

In addition, when the manipulation lever 106 is manually manipulated torotate, the engagement protrusion part 110 c of the click lever 110 isinserted into and pressed to the first engagement concave part 107 a,the second engagement concave part 107 b, or the third engagementconcave part 107 c while sliding with respect to the outercircumferential face of the rotation plate part 107.

Thus, a feeling of a change in an engagement position is transmitted tothe hand gripping the manipulation lever 106, and thus the operator 700or the like who is performing a rotation manipulation experiences aso-called click feeling and recognizes an engagement state of theengagement protrusion part 110 c according to the size of a transmittedload, and the operator 700 or the like can easily recognize thatnecessary rotation manipulation has been completed, and can easily andsurely perform the rotation manipulation of the manipulation lever 106and surely cause the element holding frame 118 to be turned to anotherturning position.

In the state in which the element holding frame 118 is turned to thesecond turning position, the third optical element 129 held in theother-end frame part 126 of the element holding frame 118 is positionedon the optical axis to be orthogonal to the optical axis, facing thefront-rear direction as illustrated in FIGS. 49 and 50. Thus, light thathas penetrated the fourth lens groups 99 and 99 penetrates the thirdoptical element 129 and then is incident on the fifth lens groups 100and 100.

At the second turning position, the detection piece 121 c provided onthe right wall 121 of the element holding frame 118 is positionedbetween the pair of detectors 116 a and 116 a of the second positiondetection sensor 116 mounted on the right side face part 98 of the rearsupport housing 91 (refer to FIG. 51). Since the detection piece 121 cis positioned between the pair of detectors 116 a and 116 a, it isdetected that the element holding frame 118 is at the second turningposition.

As described above, since the angle formed by the intermediate framepart 124 and the one-end frame part 125 and the angle formed by theintermediate frame part 124 and the other-end frame part 126 within thevertical plane including the optical axis are all set to 135 degrees andthe angle formed by the one-end frame part 125 and the other-end framepart 126 within the vertical plane including the optical axis is set to90 degrees, the one-end frame part 125 and the second optical element128 held in the one-end frame part 125 are parallel with the opticalaxis in the state in which the element holding frame 118 is held at thesecond turning position (refer to FIG. 47).

Thus, the one-end frame part 125 and the second optical element 128 donot protrude in the direction orthogonal to the optical axis, and thusminiaturization of the medical observation device 1 in the directionorthogonal to the optical axis can be achieved.

Note that, although the example in which the manipulation lever 106 ismanually manipulated to rotate has been described above, themanipulation lever 106 may be configured to be driven with a drivingforce of a motor, or the like.

The above-described first position detection sensor 115 and the secondposition detection sensor 116 detect turning positions of the elementholding frame 118 at the intermediate position, the first turningposition, and the second turning position, and processing of respectiveimages is performed according to each of the first optical element 127,the second optical element 128, and the third optical element 129positioned on the optical axis based on the detection results of thefirst position detection sensor 115 and the second position detectionsensor 116.

Thus, since processing of respective images is performed based on thedetection results of the first position detection sensor 115 and thesecond position detection sensor 116, the images can be properlyprocessed according to the first optical element 127, the second opticalelement 128, and the third optical element 129 positioned on the opticalaxis, and functionality of the medical observation device 1 can beimproved.

In the medical observation device 1, the axial direction of the turningshaft of the element holding frame 118 is set to the directionorthogonal to the optical axis direction, and the element holding frame118 is turned and thus any of the first optical element 127, the secondoptical element 128, and the third optical element 129 is positioned onthe optical axis as described above.

Thus, since the element holding frame 118 is turned using the turningshaft whose axial direction is set to the direction orthogonal to theoptical axis direction as a fulcrum and thus any of the first opticalelement 127, the second optical element 128, and the third opticalelement 129 is positioned on the optical axis, a turning space of theelement holding frame 118 in the direction orthogonal to the opticalaxis can be small, the functionality of the medical observation device 1attained by switching the first optical element 127, the second opticalelement 128, and the third optical element 129 can be improved, andfurther miniaturization thereof in the direction orthogonal to theoptical axis can be achieved.

In addition, in the medical observation device 1, the first opticalelement 127, the second optical element 128, and the third opticalelement 129 are provided, and the first optical element 127 and thethird optical element 129 are disposed to be perpendicular to eachother.

Thus, the distance between the first optical element 127 and the thirdoptical element 129 in the direction orthogonal to the optical axisbecomes shorter, and further miniaturization of the medical observationdevice 1 in the direction orthogonal to the optical axis can beachieved.

[Others]

Although the example in which the first position detection sensor 115and the second position detection sensor 116 optically detect a turningposition of the element holding frame 118 has been described above,detecting a turning position of the element holding frame 118 is notlimited to optical detection, and other detection methods may be used.

Detecting a turning position of the element holding frame 118 can beperformed using, for example, a detection method using magnetism. As anexample of detection using magnetism, for example, there is an examplein which a magnet 130 is mounted in the element holding frame 118 andHall elements 131 and 131 are mounted on, for example, the right sideface part 98 of the rear support housing 91, as illustrated in FIGS. 52to 54. The Hall elements 131 and 131 are mounted at a position at whichthey face a movement trace of the magnet 130 according to turning of theelement holding frame 118.

Magnetic flux of the magnet 130 does not penetrate the Hall elements 131and 131 when the magnet 130 is positioned between the Hall elements 131and 131, and thus it is detected that the element holding frame 118 isat the intermediate position (refer to FIG. 52). Magnetic flux of themagnet 130 penetrates one Hall element 131 when the magnet 130 ispositioned to face the one Hall element 131, and thus it is detectedthat the element holding frame 118 is at the first turning position(refer to FIG. 53). Magnetic flux of the magnet 130 penetrates the otherHall element 131 when the magnet 130 is positioned to face the otherHall element 131, and thus it is detected that the element holding frame118 is at the second turning position (refer to FIG. 54).

By magnetically detecting a turning position of the element holdingframe 118, the turning position of the element holding frame 118 can bedetected without using detection light, there is no need for detectionlight to be incident on the imaging optical system or the image sensors105 b and 105 b, and thus deterioration in quality of captured images orvideos can be prevented.

In addition, although the example in which the three optical elementsincluding the first optical element 127, the second optical element 128,and the third optical element 129 are provided has been described above,the number of optical elements is arbitrary as long as it is plural, andthe number of optical elements may be two, or four or more.

However, even when four or more optical elements are provided, it isdesirable that, when any one of the optical elements is positioned onthe optical axis, at least one of the other optical elements be parallelwith the optical axis and at least any two of the optical elements bepositioned to be orthogonal to each other.

An example in which five optical elements are retained in the elementholding frame 118 will be described below (refer to FIGS. 55 and 56).

The five optical elements 132, 133, 134, 135, and 136 are held in theelement holding frame 118 to be arranged in order in a turning directionof the element holding frame 118. The optical elements 132, 133, 134,135, and 136 are held in the element holding frame 118 in the turningdirection at, for example, equal angles. Each of the optical elements132, 133, 134, 135, and 136 stops at any of five turning positionslocated on the optical axis and held in the element holding frame 118.

When the optical element 136 held on one end of the element holdingframe 118 is positioned on the optical axis in this structure, it isconfigured such that a path S of light penetrating the optical element136 is not blocked by the portion of the element holding frame 118holding the optical element 132 that is held on the other end of theelement holding frame 118 (refer to FIG. 56). In addition, when theoptical element 132 held on the other end of the element holding frame118 is positioned on the optical axis, it is also configured such thatthe path of light penetrating the optical element 132 is not blocked bythe portion of the element holding frame 118 holding the optical element136 held on the one end of the element holding frame 118.

Thus, in the state in which each of the optical elements 132, 133, 134,135, and 136 is positioned on the optical axis, light penetrating eachof the optical elements 132, 133, 134, 135, and 136 is not blocked bythe element holding frame 118, and thus a satisfactory function of theimaging optical system of the medical observation device 1 can beensured.

In addition, since the number of optical elements held in the elementholding frame 118 is large and functions increase according to thenumber of held optical elements, functionality of the medicalobservation device 1 can be improved.

Furthermore, although the example in which the first optical element127, the second optical element 128, and the third optical element 129with different functions and types are provided as optical elements hasbeen described above, the technology is not limited to using opticalelements with different functions and types, and optical elements withdifferent thicknesses, sizes, and shapes may be used. Particularly, aplurality of neutral density (ND) filters having different lighttransmittance may be used as optical elements.

Furthermore, although the example in which optical filters are used asoptical elements has been described above, the optical elements are notlimited to the optical filters, and other optical elements such as alens, a polarizing element, and a shutter may be used as the opticalelements.

In addition, although the example in which the first optical element127, the second optical element 128, and the third optical element 129are switched has been descried above, a configuration in which, in themedical observation device 1, optical elements having differentfunctions and types can be switched in left-eye and right-eye imagingoptical systems is also possible. For example, the left-eye imagingoptical system has an optical element that is an infrared cut-offfilter, the right-eye imaging optical system has an optical element thatis a special light observation filter that allows only excitationwavelengths of fluorochrome to penetrate therethrough, and thusdifferent images are captured in the left-eye and right-eye imagingoptical systems.

Furthermore, a configuration in which a seal member such as a gasket isdisposed between the front part support housing 14 and the intermediatesupport housing 29 or between the intermediate support housing 29 andthe rear support housing 91 to suppress invasion of foreign substancesinto the inside of the lens barrel 10 is also possible.

Moreover, although the example in which moving objects that are movedthrough manipulation of the driving motor 56 and the manipulation object77 are zoom lens groups such as the second zoom lens groups 33 and 33has been described above, a moving object moved through manipulation ofa driving motor or a manipulation object is not limited to a zoom lensgroup. A moving object moved through manipulation of a driving motor anda manipulation object may have another structure, for example, a focuslens group, an iris mechanism, or the like.

Note that the medical observation device of the present technology canbe applied not only to an imaging device that captures images of lesionsas described above but also, for example, to a video microscope, or thelike.

[Present Technology]

Additionally, the present technology may also be configured as below.

(1)

A medical observation device including:

an imaging optical system configured to capture an image of a subject;

an image sensor configured to photoelectrically convert the image of thesubject captured by the imaging optical system;

a driving force transmission mechanism configured to have a transmissiongear and to transmit a driving force to a moving object;

a manual manipulation knob configured to be manipulated to rotate in anaxial rotation direction of a fulcrum shaft and to be capable of movingbetween a first position and a second position in an axial direction ofthe fulcrum shaft;

a switch gear configured to be connected to the manual manipulation knoband to be integrated with the manual manipulation knob and rotate in theaxial rotation direction, and to be integrated with the manualmanipulation knob and move in the axial direction between a meshingposition and a non-meshing position; and

a driving motor configured to give a driving force to the moving object,

wherein meshing of the switch gear and the transmission gear is releasedat the non-meshing position, and

the switch gear and the transmission gear mesh with each other at themeshing position.

(2)

The medical observation device according to (1),

wherein the driving motor is set to be in a non-driving state when theswitch gear is moved to the meshing position.

(3)

The medical observation device according to (1) or (2),

wherein a gear box in which at least the transmission gear and theswitch gear are disposed is provided, and

a direction from the first position toward the second position is set toa drawn-out direction of the manual manipulation knob from the gear box.

(4)

The medical observation device according to (3),

wherein the gear box in which at least the transmission gear and theswitch gear are disposed is provided,

a movement regulation part is provided in the gear box, and

a regulated part that is capable of contact with the movement regulationpart when the manual manipulation knob is moved from the first positiontoward the second position is provided in the manual manipulation knob.

(5)

The medical observation device according to any of (2) to (4),

wherein a gear box in which at least the transmission gear and theswitch gear are disposed and a first holding engagement part and asecond holding engagement part are included is provided,

a holding member having a position holding part is mounted in the manualmanipulation knob,

when the manual manipulation knob is moved to the first position, theposition holding part is engaged with the first holding engagement partand the switch gear is held at the non-meshing position, and

when the manual manipulation knob is moved to the second position, theposition holding part is engaged with the second holding engagement partand the switch gear is held at the meshing position.

(6)

The medical observation device according to (5),

wherein the position holding part is capable of elastic deformation,

the position holding part slides to the gear box in an elasticallydeformed state during movement of the manual manipulation knob, and

the position holding part is elastically restored and engaged with thefirst holding engagement part or the second holding engagement part.

(7)

The medical observation device according to any of (1) to (6),

wherein the transmission gear is capable of moving in an axialdirection, and

a meshing assisting spring configured to urge the transmission gear in adirection to get the transmission gear close to the switch gear in theaxial direction is provided.

(8)

A lens barrel of a medical observation device including:

an imaging optical system configured to capture an image of a subject;

an image sensor configured to photoelectrically convert the image of thesubject captured by the imaging optical system;

a driving force transmission mechanism configured to have a transmissiongear and to transmit a driving force to a moving object;

a manual manipulation knob configured to be manipulated to rotate in anaxial rotation direction of a fulcrum shaft and to be capable of movingbetween a first position and a second position in an axial direction ofthe fulcrum shaft;

a switch gear configured to be connected to the manual manipulationknob, and to be integrated with the manual manipulation knob and rotatein the axial rotation direction, and to be integrated with the manualmanipulation knob and move in the axial direction between a meshingposition and a non-meshing position; and

a driving motor configured to give a driving force to the moving object,

wherein meshing of the switch gear and the transmission gear is releasedat the non-meshing position, and

the switch gear and the transmission gear mesh with each other at themeshing position.

REFERENCE SIGNS LIST

-   1 medical observation device-   10 lens barrel-   56 driving motor-   71 gear box-   73 b movement regulation part-   74 b first holding engagement part-   74 c second holding engagement part-   76 fulcrum shaft-   79 b switch gear-   80 manual manipulation knob-   81 b regulated part-   83 holding member-   85 a position holding part-   86 transmission gear-   89 meshing assisting spring-   105 b image sensor

1. A medical observation device comprising: an imaging optical systemconfigured to capture an image of a subject; an image sensor configuredto photoelectrically convert the image of the subject captured by theimaging optical system; a driving force transmission mechanismconfigured to have a transmission gear and to transmit a driving forceto a moving object; a manual manipulation knob configured to bemanipulated to rotate in an axial rotation direction of a fulcrum shaftand to be capable of moving between a first position and a secondposition in an axial direction of the fulcrum shaft; a switch gearconfigured to be connected to the manual manipulation knob and to beintegrated with the manual manipulation knob and rotate in the axialrotation direction, and to be integrated with the manual manipulationknob and move in the axial direction between a meshing position and anon-meshing position; and a driving motor configured to give a drivingforce to the moving object, wherein meshing of the switch gear and thetransmission gear is released at the non-meshing position, and theswitch gear and the transmission gear mesh with each other at themeshing position.
 2. The medical observation device according to claim1, wherein the driving motor is set to be in a non-driving state whenthe switch gear is moved to the meshing position.
 3. The medicalobservation device according to claim 1, wherein a gear box in which atleast the transmission gear and the switch gear are disposed isprovided, and a direction from the first position toward the secondposition is set to a drawn-out direction of the manual manipulation knobfrom the gear box.
 4. The medical observation device according to claim3, wherein the gear box in which at least the transmission gear and theswitch gear are disposed is provided, a movement regulation part isprovided in the gear box, and a regulated part that is capable ofcontact with the movement regulation part when the manual manipulationknob is moved from the first position toward the second position isprovided in the manual manipulation knob.
 5. The medical observationdevice according to claim 1, wherein a gear box in which at least thetransmission gear and the switch gear are disposed and a first holdingengagement part and a second holding engagement part are included isprovided, a holding member having a position holding part is mounted inthe manual manipulation knob, when the manual manipulation knob is movedto the first position, the position holding part is engaged with thefirst holding engagement part and the switch gear is held at thenon-meshing position, and when the manual manipulation knob is moved tothe second position, the position holding part is engaged with thesecond holding engagement part and the switch gear is held at themeshing position.
 6. The medical observation device according to claim5, wherein the position holding part is capable of elastic deformation,the position holding part slides to the gear box in an elasticallydeformed state during movement of the manual manipulation knob, and theposition holding part is elastically restored and engaged with the firstholding engagement part or the second holding engagement part.
 7. Themedical observation device according to claim 1, wherein thetransmission gear is capable of moving in an axial direction, and ameshing assisting spring configured to urge the transmission gear in adirection to get the transmission gear close to the switch gear in theaxial direction is provided.
 8. A lens barrel of a medical observationdevice comprising: an imaging optical system configured to capture animage of a subject; an image sensor configured to photoelectricallyconvert the image of the subject captured by the imaging optical system;a driving force transmission mechanism configured to have a transmissiongear and to transmit a driving force to a moving object; a manualmanipulation knob configured to be manipulated to rotate in an axialrotation direction of a fulcrum shaft and to be capable of movingbetween a first position and a second position in an axial direction ofthe fulcrum shaft; a switch gear configured to be connected to themanual manipulation knob, and to be integrated with the manualmanipulation knob and rotate in the axial rotation direction, and to beintegrated with the manual manipulation knob and move in the axialdirection between a meshing position and a non-meshing position; and adriving motor configured to give a driving force to the moving object,wherein meshing of the switch gear and the transmission gear is releasedat the non-meshing position, and the switch gear and the transmissiongear mesh with each other at the meshing position.